Yc2HD83F

11 . When a patient with one strong side and one weak side is being assisted onto an x-ray table, the radiographer should 
2(A) position the weaker side closer to the table 
3(B) position the stronger side closer to the table 
4(C) let the patient manage without assistance 
5(D) lift the patient carefully onto the table
6 ------------------------------------------------ (B) When transferring patients, always help the patient transfer toward the strong side. Be certain that the wheels of stretchers and wheelchairs are locked during transfer. When assisting a patient in changing, first remove clothing from the unaffected side. If this is done, removing clothing from the affected side will require less movement and effort.
7
82 . Honor Code violations that can prevent a radiography student from meeting ARRT certification requirements include 
91. failing one or more courses in the radiography program 
102. being suspended from the radiography program 
113. being dismissed/ expelled from a radiography program 
12(A) 1 only 
13(B) 1 and 2 only 
14(C) 2 and 3 only 
15(D) 1, 2, and 3
16 ------------------------------------------------ (C) The word honor implies regard for the standards of one's profession, a refusal to lie/ deceive, an uprightness of character or action, a trustworthiness and incorruptibility. Other words used to describe these qualities are honesty, integrity, and probity. These are qualities required of students and health care professionals. This honor/ integrity can only be achieved in an environment where intellectual honesty and personal integrity are highly valued— and where the responsibility for communicating and maintaining these standards is widely shared. The ARRT publishes an important document regarding Honor Code violations. In order to meet ARRT certification requirements, candidates for the ARRT examination must answer the question: "Have you ever been suspended, dismissed, or expelled from an educational program that you have attended?" . . . in addition to reading and signing the "Written Consent under FERPA," allowing the ARRT to obtain specific parts of their educational records concerning violations to an honor code if the student has ever been suspended, dismissed, or expelled from an educational program attended. If the applicant answers "yes" to that question he or she must include an explanation and documentation of the situation with the completed application for certification. If the applicant has any doubts, he or she should contact the ARRT Ethics Requirements Department at (651) 687-0048, ext. 8580. [Source: The American Registry of Radiologic Technologists Standards of Ethics.
17
183 . For medicolegal reasons, radiographic images are required to include all the following information except 
19(A) the patient's name and/ or identification number 
20(B) the patient's birth date 
21(C) a right- or left-side marker 
22(D) the date of the examination
23 ------------------------------------------------ . (B) Every radiographic image must include (1) the patient's name or ID number, (2) the side marker, right or left; (3) the date of the examination; and (4) the identity of the institution or office. Additional information may be included: the patient's birth date or age, name of the attending physician, and the time of day. When multiple examinations (e.g., chest examinations or small bowel images) of a patient are made on the same day, it becomes crucial that the time the radiographs were taken be included on the image. This allows the physician to track the patient's progress.
24
254 . A radiographer who discloses confidential patient information to unauthorized individuals can be found guilty of 
26(A) libel 
27(B) invasion of privacy 
28(C) slander 
29(D) defamation
30 ------------------------------------------------ (B) A radiographer who discloses confidential information to unauthorized individuals may be found guilty of invasion of privacy. If the disclosure is in some way detrimental or otherwise harmful to the patient, the radiographer may also be accused of defamation. Spoken defamation is slander; written defamation is libel.
31
325 . An iatrogenic infection is one caused by 
33(A) physician intervention 
34(B) blood-borne pathogens 
35(C) chemotherapy
36(D) infected droplets
37 ------------------------------------------------ (A) The prefix iatr- is from the Greek iatros, meaning "physician." An iatrogenic infection is one caused by physician intervention or by medical or diagnostic treatment/ procedures. Examples include infection following surgery and nausea or other illness following prescribed drug use.
38
396 . A vasomotor effect experienced after injection of a contrast agent is characterized by all of the following symptoms except 
40(A) nausea 
41(B) syncope 
42(C) hypotension 
43(D) anxiety
44 ------------------------------------------------ (C) Reactions to contrast agents are named and categorized according to the body system( s) affected, the nature of the reaction (i.e., allergic vs. nonallergic), and its severity (i.e., mild, moderate, or severe). These reactions are categorized as vasomotor (a nonallergic reaction), anaphylactic (allergic reaction), vasovagal (life-threatening), and acute renal failure (renal shutdown). Vasomotor effects are principally emotional and anxiety-based. They are characterized by anxiety, syncope , nausea, lightheadedness, and sometimes, a few hives. The patient usually just requires reassurance and not medical attention . An anaphylactic reaction is a true allergic reaction to e.g. iodinated media and can lead to a life-threatening situation. Immediate medical attention is required. Symptoms of anaphylactic reaction include laryngo/ bronchospasm, hypotension, moderate to severe urticaria, angioedema, and tachycardia . A vasovagal reaction is life-threatening and requires a declared emergency (" code"). Symptoms of a vasovagal reaction include bradycardia, hypotension, and no detectable pulse. The fourth type of reaction, acute renal failure, may not manifest for up to 48 hours following injection of the contrast agent. Patients should notify their physician if they experience any changes in their urinary habits or any other atypical symptoms. Treatment would include hydration, dispensation of a diuretic (e.g., Lasix), and possibly even renal dialysis.
45
467 . The higher the gauge number of an intravenous (IV) needle, 
47(A) the larger is its diameter 
48(B) the greater is its length 
49(C) the smaller is its diameter 
50(D) the shorter its length
51 ------------------------------------------------ (C) The diameter of a needle is the needle's gauge. The higher the gauge number, the smaller is the diameter and the thinner is the needle. For example, a very tiny-gauge needle (25 gauge) may be used on a pediatric patient for an IV injection, whereas a large-gauge needle (16 gauge) may be used for donating blood. The hub of a needle is the portion of the needle that attaches to a syringe. The length of the needle varies depending on its use. A longer needle is needed for intramuscular injections, whereas a shorter needle is used for subcutaneous injections. The bevel of the needle is the slanted tip of the needle. For IV injections , the bevel always should face up.
52
538 . Demonstration of which anatomic structures require( s) ingestion of barium sulfate suspension? 
541. Duodenum 
552. Pylorus 
563. Ilium 
57(A) 1 only 
58(B) 1 and 2 only 
59(C) 2 and 3 only 
60(D) 1, 2, and 3
61 ------------------------------------------------ (B) Oral administration of barium sulfate is used to demonstrate the upper digestive system— the esophagus, fundus, body, and pylorus of the stomach— and barium progression through the small bowel. The small bowel includes the duodenum, jejunum, and ileum (ilium is part of the pelvis).
62
639 . Which of the following drugs is used to treat dysrhythmias?
64(A) Epinephrine 
65(B) Lidocaine 
66(C) Nitroglycerin 
67(D) Verapamil
68 ------------------------------------------------ (B) Lidocaine ( Xylocaine) is an antiarrhythmic used to prevent or treat cardiac arrhythmias (dysrhythmia). Epinephrine (Adrenalin) is a bronchodilator. Bronchodilators may be administered in a spray mister, such as for asthma, or by injection to relieve severe bronchospasm. Nitroglycerin and verapamil are vasodilators. Vasodilators permit increased blood flow by relaxing the walls of the blood vessels.
69
7010 . Examples of COPD include 
711. bronchitis 
722. pulmonary emphysema 
733. asthma 
74(A) 1 only 
75(B) 1 and 2 only
76(C) 2 and 3 only 
77(D) 1, 2, and 3
78 ------------------------------------------------ (D) Chronic obstructive pulmonary disease (COPD) is the abbreviation for chronic obstructive pulmonary disease; it refers to a group of disorders, including bronchitis, emphysema, asthma, and bronchiectasis. COPD is irreversible and decreases the ability of the lungs to perform their ventilation functions. There is often less than half the normal expected maximal breathing capacity.
79
8011 . Administration of contrast agents for radiographic demonstration of the spinal canal is performed by which of the following parenteral routes? 
81(A) Subcutaneous 
82(B) Intravenous 
83(C) Intramuscular 
84(D) Intrathecal
85 ------------------------------------------------ (D) A parental route of drug administration is one that bypasses the digestive system. The five parenteral routes require different needle placements: under the skin (subcutaneous), through the skin and into the muscle (intramuscular), between the layers of the skin (intradermal), into a vein (intravenous), and into the subarachnoid space (intrathecal).
86
8712 . Accidental injection of medication or contrast medium into tissues around a vein is termed 
88(A) extravasation 
89(B) hematoma 
90(C) venipuncture 
91(D) collateral circulation
92 ------------------------------------------------ (A) Extravasation occurs when medication or contrast medium is injected into the tissues surrounding a vein rather than into the vein itself. It can happen when the patient's veins are particularly deep and/ or small. If this happens, the needle should be removed, pressure applied to prevent formation of a hematoma, and then hot packs applied to relieve pain. The antecubital vein is the most commonly used venipuncture site for contrast medium administration.
93
9413 . Which of the following can be transmitted via infected blood? 
951. HBV 
962. AIDS 
973. TB 
98(A) 1 only 
99(B) 1 and 2 only 
100(C) 2 and 3 only 
101(D) 1, 2, and 3
102 ------------------------------------------------ (B) Epidemiologic studies indicate that HIV and acquired immunodeficiency syndrome (AIDS) can be transmitted only by intimate contact with blood or body fluids of an infected individual . This can occur through the sharing of contaminated needles, through sexual contact, from mother to baby at childbirth , and from transfusion of contaminated blood. HIV and AIDS cannot be transmitted by inanimate objects. Hepatitis B virus (HBV) is another blood-borne infection that affects the liver. It is thought that more than 1 million people in the United States have chronic hepatitis B and, as such, can transmit the disease to others. Acid-fast bacillus (AFB) isolation is employed with patients suspected or known to be infected with tuberculosis (TB). AFB isolation requires that the patient wear a mask to avoid the spread of acid-fast bacilli (in bronchial secretions) during coughing.
103
10414 . The mechanical device used to correct an ineffectual cardiac rhythm is a 
105(A) defibrillator 
106(B) cardiac monitor 
107(C) crash cart 
108(D) resuscitation bag
109 ------------------------------------------------ (A) The mechanical device used to correct an ineffectual cardiac ventricular rhythm is a defibrillator. The two paddles attached to the unit are placed on a patient's chest and used to introduce an electric current in an effort to correct the dysrhythmia. Automatic implantable cardioverter defibrillators (AICDs) are devices that are implanted in the body and that deliver a small shock to the heart if a life-threatening dysrhythmia occurs. A cardiac monitor is used to display, and sometimes record, electrocardiographic (ECG) readings and some pressure readings. A crash cart is a supply cart with various medications and equipment necessary for treating a patient who is suffering from a myocardial infarction or some other serious medical emergency. It is checked and restocked periodically. A resuscitation bag is used for ventilation, such as during CPR.
110
11115 . You have encountered a person who is apparently unconscious. Although you open his airway, there is no rise and fall of the chest, and you can hear no breath sounds. You should 
112(A) begin mouth-to-mouth rescue breathing, giving two full breaths 
113(B) proceed with the Heimlich maneuver 
114(C) begin external chest compressions at a rate of 80 to 100 compressions/ min 
115(D) begin external chest compressions at a rate of at least 100 compressions/ min
116 ------------------------------------------------ (A) The victim's airway should first be opened. This is accomplished by tilting back the head and lifting the chin. However, if the victim may have suffered a spinal cord injury, the spine should not be moved, and the airway should be opened using the jaw-thrust method. The rescuer next listens to breathing sounds and watches for the rise and fall of the chest to indicate breathing. If there is no breathing, the rescuer pinches the victim's nose and delivers two full breaths via mouth-to-mouth rescue breathing. If rise and fall of the chest still are not present, the Heimlich maneuver is instituted. If ventilation does not take place during the two full breaths, the victim's circulation is checked next (using the carotid artery). If there is no pulse, external chest compressions are begun at a rate of 80 to 100 compressions/ min for adults and at least 100 compressions/ min for infants.
117
11816 . In classifying IV contrast agents, the total number of dissolved particles in solution per kilogram of water defines 
119(A) osmolality 
120(B) toxicity 
121(C) viscosity 
122(D) miscibility
123 ------------------------------------------------ (A) In classifying contrast agents, the total number of dissolved particles in solution per kilogram of water defines the osmolality of the contrast agent. The toxicity defines how noxious or harmful a contrast agent is. Contrast agents with low osmolality have been found to cause less tissue toxicity than the ionic IV contrast agents. The viscosity defines the thickness or concentration of the contrast agent. The viscosity of a contrast agent can affect its injection rate. A thicker, or more viscous, contrast agent will be more difficult to inject (more pressure is needed to push the contrast agent through the syringe and needle or the angiocatheter). The miscibility of a contrast agent refers to its ability to mix with body fluids, such as blood. Miscibility is an important consideration in preventing thrombus formation. It is generally preferable to use a contrast agent with low osmolality and low toxicity because such an agent is safer for the patient and less likely to cause any untoward reactions. When ionic and nonionic contrast agents are compared, a nonionic contrast agent has a lower osmolality. To further understand osmolality, remember that whenever IV contrast media are introduced, there is a notable shift in fluid and ions. This shift is caused by an inflow of water from interstitial regions into the vascular compartment, which increases the blood volume and cardiac output. Consequently, there will be an increase in systemic arterial pressure and peripheral vascular resistance with peripheral vasodilation. In addition, the pulmonary pressure and heart rate increase. When the effects of osmolality on the patient are understood, it becomes clear that an elderly patient or one with cardiac disease or impaired circulation would greatly benefit from the use of an agent with lower osmolality.
124
12517 . Which of the following is a violation of correct sterile technique? 
126(A) Gowns are considered sterile in the front down to the waist, including the arms. 
127(B) Sterile gloves must be kept above the waist level. 
128(C) Persons in sterile dress should pass each other face to face. 
129(D) A sterile field should not be left unattended.
130 ------------------------------------------------ . (C) Persons in sterile dress should not pass each other face to face. Rather, they should pass each other back to back to avoid contaminating each other. Gowns are considered sterile in the front down to the waist, including the arms. Sterile gloves must be kept above the waist level. If the hands are accidentally lowered or placed behind the back, they are no longer sterile. A sterile field should not be left unattended. Sterile fields should be set up immediately prior to a procedure and should be covered with a sterile drape if a few moments are to elapse before the procedure can begin. A sterile field should be monitored constantly to be certain that it has not been contaminated.
131
13218 . Misunderstandings between cultures can happen as a result of 
1331. looking directly into someone's eyes 
1342. the use of certain gestures 
1353. standing too close while speaking to another 
136(A) 1 only 
137(B) 1 and 2 only 
138(C) 2 and 3 only 
139(D) 1, 2, and 3
140 ------------------------------------------------ (D) Misunderstandings between cultures can occur as a result of the use of gestures, which have different meanings in different countries . In the US and Europe, the "thumbs up" gesture has a positive implication. However, it is considered rude in Australia and obscene in the Middle East. Other examples of potentially misunderstood gestures include: if you compliment a Mexican child , you must touch the head, while in Asia it is not acceptable to touch the head of a child; in the Philippines, it is rude to beckon with the index finger; furthermore, in the US, people are comfortable speaking about 18 inches apart, while in the Middle East, people stand much closer together when they talk ; in England, people stand further apart.
141
14219 . The legal doctrine respondeat superior means which of the following?
143(A) A matter settled by precedent. 
144(B) A thing or matter settled by justice. 
145(C) The thing speaks for itself. 
146(D) Let the master answer.
147 ------------------------------------------------ (D) Respondeat superior is a phrase meaning "let the master answer" or "the one ruling is responsible." If a radiographer were negligent, there may be an attempt to prove that the radiologist was responsible because the radiologist oversees the radiographer. The legal doctrine res ipsa locquitur relates to a thing or matter that speaks for itself. For instance, if a patient went into the hospital to have a kidney stone removed and ended up with an appendectomy, that speaks for itself, and negligence can be proven. Res judicata means a thing or matter settled by justice. Stare decisis refers to a matter settled by precedent.
148
14920 . Some proteins in latex can produce mild to severe allergic reactions. Medical equipment that could contain latex includes 
1501. tourniquets 
1512. enema tips 
1523. catheters 
153(A) 1 only 
154(B) 1 and 2 only 
155(C) 2 and 3 only 
156(D) 1, 2, and 3
157 ------------------------------------------------ (D) Medical equipment that could contain latex includes disposable gloves, tourniquets, blood pressure cuffs, stethoscopes, IV tubing, oral and nasal airways, enema tips, endotracheal tubes, syringes, electrode pads, catheters, wound drains, and injection ports. It should be noted that when powdered latex gloves are changed, latex protein/ powder particles get into the air, where they can be inhaled and come in contact with body membranes. Studies have indicated that when unpowdered gloves are worn, there are extremely low levels of the allergy-producing proteins present.
158
15921 . Conditions in which there is a lack of normal bone calcification include 
1601. rickets 
1612. osteomalacia 
1623. osteoarthritis 
163(A) 1 only
164(B) 1 and 2 only 
165(C) 2 and 3 only 
166(D) 1, 2, and 3
167 ------------------------------------------------ (B) Rickets and osteomalacia are disorders in which there is softening of bone. Rickets results from a deficiency of vitamin D and usually is found affecting the growing bones of young children. The body's weight on the soft bones of the legs results in bowed and misshapen legs. Osteomalacia is an adult condition in which new bone fails to calcify. It is a painful condition and can result in easily fractured bones , especially in the lower extremities. Osteoarthritis is seen often in the elderly and is characterized by degeneration of articular cartilage in adjacent bones. The resulting rubbing of bone against bone results in pain and deterioration.
168
16922 . A quantity of medication introduced intravenously over a period of time is termed 
170(A) an IV push 
171(B) an infusion 
172(C) a bolus 
173(D) a hypodermic
174 ------------------------------------------------ (B) Quantities of medication can be dispensed intravenously over a period of time via an IV infusion. A special infusion pump may be used to precisely regulate the quantity received by the patient. An IV push refers to a rapid injection; the term bolus refers to the quantity of material being injected. The term hypodermic refers to administration of medication by any route other than oral.
175
17623 . Anaphylactic shock manifests early symptoms that include 
1771. dysphagia 
1782. itching of palms and soles 
1793. constriction of the throat 
180(A) 1 only 
181(B) 2 only 
182(C) 2 and 3 only 
183(D) 1, 2, and 3
184 ------------------------------------------------ (D) Adverse reactions to the intravascular administration of iodinated contrast media are not uncommon, and although the risk of a life-threatening reaction is relatively low, the radiographer must be alert to recognize the situation and deal with it effectively should a serious reaction occur. A minor reaction is characterized by flushed appearance and nausea and, occasionally, by vomiting and a few hives. Early symptoms of a possible anaphylactic reaction include constriction of the throat, possibly because of laryngeal edema, dysphagia (difficulty swallowing), and itching of the palms and soles. The radiographer must maintain the patient's airway, summon the radiologist, and call a "code."
185
18624 . The legal document or individual authorized to make an individual's health care decisions, should the individual be unable to make them for himself or herself, is the 
1871. advance health care directive 
1882. living will 
1893. health care proxy 
190(A) 1 only 
191(B) 1 and 2 only 
192(C) 2 and 3 only 
193(D) 1, 2, and 3
194 ------------------------------------------------ (D) The patient's rights can be exercised on the patient's behalf by a designated surrogate or proxy decision maker if the patient lacks decision-making capacity, is legally incompetent , or is a minor. Many people believe that potential legal and ethical issues can be avoided by creating an advance health care directive or living will. Since all persons have the right to make decisions regarding their own health care, this legal document preserves that right in the event an individual is unable to make those decisions. An advance health care directive, or living will , names the health care proxy authorized to make all health care decisions and can include specifics regarding DNR (Do not resuscitate), DNI (Do not intubate), and/ or other end-of-life decisions.
195
19625 . In which stage of infection do the infective microbes begin to multiply? 
197(A) Latent period 
198(B) Incubation period 
199(C) Disease phase
200(D) Convalescent phase
201 ------------------------------------------------ (B) There are four stages of infection. In the initial phase, the latent period, the infection is introduced and lies dormant. As soon as the microbes begin to shed, the infection becomes communicable. The microbes reproduce (during the incubation period), and during the actual disease period, signs and symptoms of the infection may begin . The infection is most active and communicable at this point. As the patient fights off the infection and the symptoms regress, the convalescent (recovery) phase occurs.
202
20326 . When performing cardiopulmonary resuscitation (CPR) on an infant, it is recommended that the number of compressions per minute, compared with that for an adult, 
204(A) remain the same 
205(B) double 
206(C) decrease 
207(D) increase
208 ------------------------------------------------ (D) The heart rate of an infant is much faster than that of an adult; therefore, the number of compressions per minute is also greater. Infant CPR requires five compressions to one breath. There should be at least 100 compressions/ min.
209
21027 . All the following statements regarding hand hygiene and skin care are correct except 
211(A) hands should be cleansed before and after each patient examination 
212(B) faucets should be opened and closed with paper towels 
213(C) hands should be smooth and free from chapping 
214(D) any cracks or abrasions should be left uncovered to facilitate healing
215 ------------------------------------------------ . (D) Today we know that the most important precaution in the practice of aseptic technique is proper hand hygiene. The radiographer's hands should be thoroughly washed with soap and warm running water for at least 15 seconds before and after each patient examination, or by using an alcohol sanitizer . If the faucet cannot be operated with the knee, it should be opened and closed using paper towels (to avoid contamination of or by the faucet). The radiographer's uniform should not touch the sink. The hands and forearms should always be kept lower than the elbows; care should be taken to wash all surfaces and between fingers . Hand lotions should be used to prevent hands from chapping; broken skin permits the entry of microorganisms. Disinfectants, antiseptics, and germicides are substances used to kill pathogenic bacteria; they are frequently used in hand hygiene substances. Alcohol-based hand sensitizers have been recommended as an alternative to handwashing with soap and water, except when there is visible soiling or after caring for a patient with Clostridium difficile infection.
216
21728 . A patient suffering from orthopnea would experience the least discomfort in which body position? 
218(A) Fowler
219(B) Trendelenburg 
220(C) Recumbent 
221(D) Erect
222 ------------------------------------------------ (D) Orthopnea is a respiratory condition in which the patient has difficulty breathing (dyspnea) in any position other than erect. The patient is usually comfortable in the erect, standing, or seated position. The Trendelenburg position places the patient's head lower than the rest of the body, the Fowler position is a semierect position, and the recumbent position is lying down.
223
22429 . When a patient arrives in the radiology department with a urinary Foley catheter bag, it is important to 
225(A) place the drainage bag above the level of the bladder 
226(B) place the drainage bag at the same level as the bladder 
227(C) place the drainage bag below the level of the bladder 
228(D) clamp the Foley catheter
229 ------------------------------------------------ (C) When caring for a patient with an indwelling Foley catheter, place the drainage bag and tubing below the level of the bladder to maintain the gravity flow of urine. Placement of the tubing or bag above or level with the bladder will allow backflow of urine into the bladder. This reflux of urine can increase the chance of a urinary tract infection (UTI).
230
23130 . Instruments required to assess vital signs include 
2321. a stethoscope 
2332. a sphygmomanometer 
2343. a watch with a second hand 
235(A) 1 only 
236(B) 1 and 2 only 
237(C) 1 and 3 only 
238(D) 1, 2, and 3
239 ------------------------------------------------ (D) The four vital signs are temperature, pulse, respiration, and blood pressure. Because radiographers may be required to take vital signs in an emergency , they should practice these skills. A thermometer is required to measure a patient's temperature. A watch with a second hand is required to measure a patient's pulse and respiration. To measure blood pressure, a blood pressure cuff, sphygmomanometer, and stethoscope are required . This is the skill that the radiographer should practice most frequently because it is the one most likely to be needed in an emergency situation.
240
24131 . Hirschsprung disease, or congenital megacolon, is related to which of the following age groups? 
242(A) Neonate 
243(B) Toddler 
244(C) Adolescent 
245(D) Adult
246 ------------------------------------------------ (A) Hirschsprung disease, or congenital megacolon, is caused by the absence of some or all of the bowel ganglion cells— usually in the rectosigmoid area but occasionally more extensively. Hirschsprung disease is the most common cause of lower GI obstruction in neonates and is treated surgically by excision of the affected area followed by reanastomosis with normal, healthy bowel. Hirschsprung disease is diagnosed by barium enema or, in mild cases, by rectal biopsy.
247
24832 . Possible side effects of an iodinated contrast medium that is administered intravenously include all the following except 
2491. a warm, flushed feeling 
2502. altered taste 
2513. rash and hives 
252(A) 1 only 
253(B) 3 only
254(C) 2 and 3 only 
255(D) 1, 2, and 3
256 ------------------------------------------------ (B) Nonionic, low-osmolality iodinated contrast agents are associated with far fewer side effects and reactions than ionic, higher osmolality contrast agents. A side effect is an effect that is unintended but possibly expected and fundamentally not harmful. An adverse reaction is a harmful unintended effect. Possible side effects of iodinated contrast agents include a warm, flushed feeling, a metallic taste in the mouth, nausea, headache, and pain at the injection site. Adverse reactions include itching, anxiety, rash or hives, vomiting, sneezing, dyspnea, and hypotension.
257
25833 . In the blood pressure reading 145/ 75 mmHg, what does 145 represent? 
2591. The phase of relaxation of the cardiac muscle tissue 
2602. The phase of contraction of the cardiac muscle tissue 
2613. A higher-than-average diastolic pressure 
262(A) 1 only 
263(B) 2 only 
264(C) 1 and 3 only 
265(D) 2 and 3 only
266 ------------------------------------------------ (B) The normal blood pressure range for men and women is a 110 to 140 mm Hg systolic reading (left number) and a 60 to 80 mm Hg diastolic reading (right number). Systolic pressure is the contraction phase of the left ventricle , and diastolic pressure is the relaxation phase in the heart cycle.
267
26834 . Facsimile transmission of health information is 
2691. not permitted 
2702. permitted for urgently needed patient care 
2713. permitted for third-party payer hospitalization certification 
272(A) 1 only 
273(B) 2 only 
274(C) 2 and 3 only 
275(D) 1, 2, and 3
276 ------------------------------------------------ (C) Facsimile transmission of health information is convenient but should be used only to address immediate and urgent patient needs— and every precaution must be taken to ensure its confidentiality. It should be used only with prior patient authorization, when urgently needed for patient care, or when required for third-party payer ongoing hospitalization certification. These recommendations are made by the American Health Information Management Association (AHIMA).
277
27835 . Forms of intentional misconduct include 
2791. slander 
2802. invasion of privacy 
2813. negligence 
282(A) 1 only 
283(B) 2 only 
284(C) 1 and 2 only 
285(D) 1, 2, and 3
286 ------------------------------------------------ (C) Verbal defamation of another , or slander, is a type of intentional misconduct. Invasion of privacy (i.e., public discussion of privileged and confidential information) is intentional misconduct. However, if a radiographer leaves a weak patient standing alone to check images or get supplies and that patient falls and sustains an injury, that would be considered unintentional misconduct, or negligence.
287
28836 . Which of the following statements is correct with regard to assisting a patient from a wheelchair to an x-ray table? 
289(A) The wheelchair should be parallel with the x-ray table. 
290(B) The patient's weaker side should be closer to the x-ray table. 
291(C) The wheelchair should directly face the x-ray table. 
292(D) The patient's stronger side should be closer to the x-ray table.
293 ------------------------------------------------ (D) When helping a patient in or out of a wheelchair, it must first be locked. Then, the footrests must be moved up and aside to prevent the patient from tripping over them or tilting the wheelchair forward. The wheelchair should be placed at a 45-degree angle with the x-ray table or bed, with the patient's stronger side closest toward the x-ray table or bed. Once the patient is seated, the footrests should be lowered into place for the patient's comfort.
294
29537 . In her studies on death and dying, Dr. Elizabeth Kubler-Ross described the first stage of the grieving process as 
296(A) denial 
297(B) anger 
298(C) bargaining 
299(D) depression
300 ------------------------------------------------ (A) Dr. Elizabeth Kubler-Ross explains that loss requires gradual adjustment and involves several steps. The first is denial or isolation, where the individual often refuses to accept the thought of loss or death. The second step is anger, as the individual attempts to deal with feelings of helplessness. The next is bargaining, in which the patient behaves as though "being good" like a "good patient" will be rewarded by a miraculous cure or return of the loss . Once the individual acknowledges that this is not likely to happen, depression is the next step. This depression precedes acceptance, where the individual begins to deal with fate or loss.
301
30238 . You and a fellow radiographer have received an unconscious patient from a motor vehicle accident. As you perform the examination, it is important that you 
3031. refer to the patient by name 
3042. make only those statements that you would make with a conscious patient 
3053. reassure the patient about what you are doing 
306(A) 1 only 
307(B) 1 and 2 only 
308(C) 2 and 3 only
309(D) 1, 2, and 3
310 ------------------------------------------------ (D) An unconscious patient frequently is able to hear and understand all that is going on, even though he or she is unable to respond. Therefore, while performing the examination, the radiographer always should refer to the patient by name and take care to continually explain what is being done and reassure the patient.
311
31239 . A cathartic is used to 
313(A) inhibit coughing 
314(B) promote elimination of urine 
315(C) stimulate defecation 
316(D) induce vomiting
317 ------------------------------------------------ . (C) Cathartics stimulate defecation and are used in preparation for radiologic examinations of the large bowel. Diuretics are used to promote urine elimination in individuals whose tissues are retaining excessive fluid. Emetics induce vomiting, and antitussives are used to inhibit coughing.
318
31940 . When radiographing the elderly, it is helpful to 
3201. move quickly 
3212. address them by their full name 
3223. give straightforward instructions 
323(A) 1 only 
324(B) 1 and 2 only 
325(C) 2 and 3 only 
326(D) 1, 2, and 3
327 ------------------------------------------------ (C) Elderly patients (actually, most people) dislike being rushed or hurried along. They appreciate the radiographer who is caring and respectful enough to take the extra few moments necessary to progress at a slower speed. Some elderly patients are easily confused, and it is best to address them by their full name and keep instructions simple and direct. The elderly require the same respectful , dignified care as all other patients.
328
32941 . What is the needle angle usually recommended for intramuscular injections? 
330(A) 90 degrees 
331(B) 75 degrees 
332(C) 45 degrees 
333(D) 15 degrees
334 ------------------------------------------------ (A) Medications can be administered in a number of ways. Parenteral administration refers to drugs administered via intramuscular, subcutaneous , IV, or intrathecal routes— that is, any way other than by mouth. Intramuscular drug injections usually require that the needle form a 90-degree angle of injection. For subcutaneous injections, the needle should form a 45-degree angle. Intravenous injections generally require that the needle form about a 15-degree angle with the arm.
335
33642 . How should the wheelchair footrests be positioned as a patient is assisted into or out of a wheelchair? 
337(A) Accessible to the foot 
338(B) Moved aside 
339(C) Parallel to the floor 
340(D) Available for support
341 ------------------------------------------------ . (B) When helping a patient into or out of a wheelchair, it must first be locked. Then, the footrests must be moved up and aside to prevent the patient from tripping over them or tilting the wheelchair forward. The wheelchair should be placed at a 45-degree angle with the x-ray table or bed, with the patient's stronger side closest to the x-ray table or bed. Once the patient is seated, the footrests should be lowered into place for the patient's comfort.
342
34343 . An esophagram would most likely be requested for patients with which of the following esophageal disorders/ symptoms? 
3441. Varices 
3452. Achalasia 
3463. Dysphasia 
347(A) 1 only 
348(B) 1 and 2 only 
349(C) 1 and 3 only 
350(D) 1, 2, and 3
351 ------------------------------------------------ . (B) Dilated, twisted veins, or varices, of the esophagus are frequently associated with obstructive liver disease or cirrhosis of the liver. These esophageal veins enlarge and can rupture, causing serious hemorrhage. Achalasia is dilation of the esophagus as a result of the cardiac sphincter's failure to relax and allow food to pass into the stomach. Dysphasia is a speech impairment resulting from a brain lesion; it is unrelated to the esophagus. Dysphagia refers to difficulty swallowing and is the most common esophageal complaint. Hiatal hernia is another common esophageal problem; it is characterized by protrusion of a portion of the stomach through the cardiac sphincter. It is a common condition , and many individuals with the condition are asymptomatic. Each of these conditions of the esophagus may be evaluated with an esophagogram. Positions usually include the posteroanterior, right anterior oblique, and right lateral positions.
352
35344 . Which of the following may be used to effectively reduce the viscosity of contrast media? 
354(A) Warming 
355(B) Refrigeration 
356(C) Storage at normal room temperature 
357(D) Storage in a cool, dry place
358 ------------------------------------------------ (A) Iodinated contrast material can become somewhat viscous (i.e ., thick and sticky) at normal room temperatures. This makes injection much more difficult. Warming the contrast medium to body temperature serves to reduce viscosity. This may be achieved by placing the vial in warm water or putting it into a special warming oven.
359
36045 . The type of shock often associated with pulmonary embolism or myocardial infarction is classified as 
361(A) neurogenic 
362(B) cardiogenic 
363(C) hypovolemic 
364(D) septic
365 ------------------------------------------------ (B) Cardiogenic shock is related to cardiac failure and results from interference with heart function. It can occur in cases of cardiac tamponade, pulmonary embolus, or myocardial infarction. Hypovolemic shock is related to loss of large amounts of blood, either from internal bleeding or from hemorrhage associated with trauma. The type of shock associated with the pooling of blood in the peripheral vessels is classified as neurogenic shock. This occurs in cases of trauma to the central nervous system that result in decreased arterial resistance and pooling of blood in peripheral vessels. Septic shock, along with anaphylactic shock, generally is classified as vasogenic shock.
366
36746 . Which of the following must be included in a patient's medical record or chart? 
3681. Diagnostic and therapeutic orders 
3692. Medical history 
3703. Informed consent 
371(A) 1 and 2 only 
372(B) 1 and 3 only 
373(C) 2 and 3 only 
374(D) 1, 2, and 3
375 ------------------------------------------------ (D) The Joint Commission [formerly the Joint Commission on the Accreditation of Health-care Organizations (JCAHO)] is the organization that accredits health care organizations in the United States. The Joint Commission sets forth certain standards for medical records. In keeping with these standards, all diagnostic and therapeutic orders must appear in the patient's medical record or chart. In addition, patient identification information, medical history, consent forms, and any diagnostic and therapeutic reports should be part of the patient's permanent record . The patient's chart is a means of communication between various health care providers.
376
37747 . What type of precautions prevent the spread of infectious agents in droplet form? 
378(A) Contact precautions 
379(B) Airborne precautions 
380(C) Protective isolation 
381(D) Strict isolation
382 ------------------------------------------------ (B) Category-specific isolations have been replaced by transmission-based precautions: airborne, droplet, and contact. Under these guidelines, some conditions or diseases can fall into more than one category. Airborne precautions are employed with patients suspected or known to be infected with tubercle bacillus (TB), chickenpox (varicella), or measles (rubeola). Airborne precautions require that the patient wear a mask to avoid the spread of bronchial secretions or other pathogens during coughing. If the patient is unable or unwilling to wear a mask, the radiographer must wear one. The radiographer should wear gloves, but a gown is required only if flagrant contamination is likely. Patients under airborne precautions require a private, specially ventilated (negative-pressure) room. A private room is also indicated for all patients on droplet precautions, that is, with diseases transmitted via large droplets expelled from the patient while speaking, sneezing, or coughing. The pathogenic droplets can infect others when they come in contact with mouth or nasal mucosa or conjunctiva. Rubella (" German measles"), mumps, and influenza are among the diseases spread by droplet contact; a private room is required for the patient , and health care practitioners should use gowns and gloves. Any diseases spread by direct or close contact, such as MRSA, conjunctivitis, and hepatitis A, require contact precautions. Contact precautions require a private patient room and the use of gloves, masks , and gowns for anyone coming in direct contact with the infected individual or his or her environment.
383
38448 . Which of the following conditions must be met in order for patient consent to be valid? 
3851. The patient must sign the consent form before receiving sedation. 
3862. The physician named on the consent form must perform the procedure. 
3873. All the blanks on the consent form must be filled in before the patient signs the form. 
388(A) 1 and 2 only 
389(B) 1 and 3 only 
390(C) 2 and 3 only 
391(D) 1, 2, and 3
392 ------------------------------------------------ (D) All the statements in the question are true and necessary in order for patient consent to be valid. The patient must sign the consent form before receiving sedation. The physician named on the consent form must perform the procedure; no other physician should perform it. Also, the consent form should be complete prior to being signed; there should be no blank spaces on the consent form when the patient signs it. In the case of a minor, a parent or guardian is required to sign the form. If a patient is not competent, then the legally appointed guardian should sign the consent form. Remember that obtaining consent is the physician's responsibility, so the explanation of the procedural risks should be performed by the physician, not by the radiographer .
393
39449 . The Heimlich maneuver is used if a patient is 
395(A) in cardiac arrest 
396(B) choking 
397(C) having a seizure 
398(D) suffering from hiccups
399 ------------------------------------------------ (B) The Heimlich maneuver is used when a person is choking. If you suspect that an individual is choking, be certain that the airway is indeed obstructed before attempting the Heimlich maneuver. A person with a completely obstructed airway will not be able to speak or cough. If the person cannot speak or cough, then the airway is obstructed, and the Heimlich maneuver should be performed. The proper method is to stand behind the choking victim with one hand in a fist, thumb side in, midway between the navel and the xiphoid tip. Place the other hand over the closed fist with the palm open and apply pressure in and up. Repeat the thrust several times until the object is dislodged. For an infant, the procedure is modified. Four back blows are given midway between the scapulae using the heel of the hand. If the object is not dislodged, the baby is turned over (being very careful to support the baby's head and spine), and four chests thrusts are performed just below the nipple line using several fingers.
400
40150 . Each of the following is an example of a fomite except 
402(A) a doorknob 
403(B) a tick 
404(C) a spoon 
405(D) an x-ray table
406 ------------------------------------------------ (B) Many microorganisms can remain infectious while awaiting transmission to another host. A contaminated inanimate object such as a food utensil, doorknob, or IV pole is referred to as a fomite. A vector is an insect or animal carrier of infectious organisms, such as a rabid animal, a mosquito that carries malaria, or a mouse/ deer tick that carries Lyme disease. They can transmit disease through either direct or indirect contact.
407
40851 . Which of the following legal phrases defines a circumstance in which both the health care provider's and the patient's actions contributed to an injurious outcome? 
409(A) Intentional misconduct 
410(B) Contributory negligence 
411(C) Gross negligence 
412(D) None of the above
413 ------------------------------------------------ (B) A circumstance in which both the health care provider's and the patient's actions contribute to an injurious outcome is termed contributory negligence. An example would be a patient who fails to follow the physician's orders or fails to show up for follow -up care and then sues when the condition causes permanent damage. Another example would be a patient who deliberately gives false information about the ingestion of drugs, leading to adverse effects from medications administered. Most states do not completely dismiss injury if there has been negligence on the part of the health care institution, even if the patient's actions contributed substantially to the injury. Rather, comparative negligence is applied, where the percentage of the injury owing to the patient's actions is compared with the total amount of injury. A jury may decide that a physician was negligent in his or her actions, but because the patient lied about using an illegal street drug that contributed to the injurious outcome, the patient is 80% responsible for his or her condition. The party suing may be awarded $ 100,000 for injuries but actually would receive only $ 20,000. Gross negligence occurs when there is willful or deliberate neglect of the patient. Assault, battery, invasion of privacy, false imprisonment, and defamation of character all fall under the category of intentional misconduct.
414
41552 . What is the first treatment for extravasation of contrast media during an IV injection? 
416(A) Apply a hot compress.
417(B) Apply a cold compress. 
418(C) Apply pressure to the vein until bleeding stops. 
419(D) Remove the needle and locate a sturdier vein immediately.
420 ------------------------------------------------ (C) Extravasation of contrast media into surrounding tissue is potentially very painful. If it does occur, the needle should be removed and the extravasation cared for immediately (before looking for another vein). First, pressure should be applied to the vein until bleeding stops . Application of a cold pack to the affected area helps to relieve pain. Application of a warm towel at the injection site can hasten absorption of the contrast medium.
421
42253 . Which of the following diastolic pressure readings might indicate hypertension? 
423(A) 40 mm Hg 
424(B) 60 mm Hg 
425(C) 80 mm Hg 
426(D) 100 mm Hg
427 ------------------------------------------------ (D) The diastolic number is the bottom (right) number in a blood pressure reading. The normal range for diastolic pressure is considered to be 60 to 80 mm Hg. A diastolic pressure reading of 110 mm Hg might indicate hypertension. A diastolic pressure of 50 mm Hg might indicate shock. The systolic number is the top (left) number in a blood pressure reading. The normal systolic pressure range is 110 to 140 mmHg.
428
42954 . To reduce the back strain that can result from moving heavy objects, the radiographer should 
430(A) hold the object away from his or her body when lifting 
431(B) bend at the waist and pull 
432(C) pull the object 
433(D) push the object
434 ------------------------------------------------ . (D) When moving heavy objects , there are several rules that will reduce back strain. When carrying a heavy object, hold it close to your body. Your back should be kept straight; avoid twisting. When lifting an object, bend at the knees and use leg and abdominal muscles to lift (rather than your back muscles). Whenever possible, push or roll heavy objects (i.e., mobile unit), rather than pulling or lifting.
435
43655 . All the following statements regarding oxygen delivery are true except 
437(A) oxygen is classified as a drug and must be prescribed by a physician 
438(B) the rate of delivery and mode of delivery must be part of a physician order for oxygen 
439(C) oxygen may be ordered continuously or as needed by the patient 
440(D) none of the above; they are all true
441 ------------------------------------------------ (D) None of the statements in the question is false; all are true. Oxygen is classified as a drug and must be prescribed by a physician. The rate and mode of delivery of oxygen must be specified in the physician's orders. It can be ordered to be delivered continuously or as needed.
442
44356 . If an emergency trauma patient experiences hemorrhaging from a leg injury, the radiographer should 
4441. apply pressure to the bleeding site 
4452. call the emergency department for assistance 
4463. apply a pressure bandage and complete the examination 
447(A) 1 and 2 only 
448(B) 1 and 3 only 
449(C) 2 and 3 only 
450(D) 1, 2, and 3
451 ------------------------------------------------ (A) It is unlikely that the radiographer will be faced with a wound hemorrhage because bleeding from wounds is controlled before the patient is seen for x-ray examination. However, if a patient does experience hemorrhaging from a wound, you should apply pressure to the bleeding site and call for assistance. Delay can lead to serious blood loss.
452
45357 . Gas-producing powder or crystals usually are ingested preliminary to which of the following examinations? 
454(A) Double-contrast barium enema (BE) 
455(B) Double-contrast gastrointestinal (GI) series 
456(C) Oral cholecystogram 
457(D) IV urogram (IVU)
458 ------------------------------------------------ (B) A double-contrast GI examination requires that the patient ingest gas-producing powder, crystals, pills, or beverage followed by a small amount of high-density barium. The patient then may be asked to roll in the recumbent position in order to coat the gastric mucosa while the carbon dioxide expands. This procedure provides optimal visualization of the gastric walls. Although a double-contrast BE uses a negative contrast agent, it is not ingested but rather is delivered rectally. An oral cholecystogram can be performed approximately 3 hours after ingestion of special ipodate calcium granules. An IVU requires an IV injection of iodinated contrast medium
459
46058 . According to the CDC, all the following precaution guidelines are true except 
461(A) airborne precautions require that the patient wear a mask 
462(B) masks are indicated when caring for patients on MRSA precautions 
463(C) patients under MRSA precautions require a negative-pressure room 
464(D) masks are indicated when caring for a patient on droplet precautions
465 ------------------------------------------------ (C) Category-specific isolations have been replaced by transmission-based precautions: airborne, droplet, and contact. Under these guidelines, some conditions or diseases can fall into more than one category. Airborne precautions are employed with patients suspected or known to be infected with tubercle bacillus (TB), chickenpox (varicella), or measles (rubeola). Airborne precautions require that the patient wear a mask to avoid the spread of bronchial secretions or other pathogens during coughing. If the patient is unable or unwilling to wear a mask, the radiographer must wear one. The radiographer should wear gloves, but a gown is required only if flagrant contamination is likely. Patients under airborne precautions require a private, specially ventilated (negative-pressure) room. A private room is also indicated for all patients on droplet precautions, that is, with diseases transmitted via large droplets expelled from the patient while speaking, sneezing, or coughing. The pathogenic droplets can infect others when they come in contact with mouth or nasal mucosa or conjunctiva. Rubella (" German measles"), mumps, and influenza are among the diseases spread by droplet contact; a private room is required for the patient , and health care practioners should wear mask if within 3 feet of patient. Any diseases spread by direct or close contact, such as methicillin-resistant Staphylococcus aureus (MRSA), conjunctivitis, and hepatitis A, require contact precautions. Contact precautions require a private patient room and the use of gloves and gowns for anyone coming in direct contact with the infected individual or his or her environment.
466
46759 . When disposing of contaminated needles, they are placed in a special container using what procedure? 
468(A) Recap the needle, remove the syringe, and dispose of the needle. 
469(B) Do not recap the needle, remove the syringe, and dispose of the needle. 
470(C) Recap the needle and dispose of the entire syringe. 
471(D) Do not recap the needle and dispose of the entire syringe.
472 ------------------------------------------------ (D) Most needle sticks occur during attempts to recap a needle. Proper disposal of contaminated needles and syringes is becoming more vital as HIV infection, AIDS, and HBV infection reach epidemic proportions. To prevent the spread of any possible infection, handle contaminated materials as little as possible. Therefore, do not attempt to recap a needle; instead, dispose of the entire syringe with the needle attached in the special container that is available.
473
47460 . You are working in the outpatient department and receive a patient who is complaining of pain in the right hip joint; however, the requisition asks for a left femur examination. What should you do? 
475(A) Perform a right hip examination. 
476(B) Perform a left femur examination. 
477(C) Perform both a right hip and a left femur examination. 
478(D) Check with the referring physician.
479 ------------------------------------------------ (D) Although it is never the responsibility of the radiographer to diagnose a patient, it is the responsibility of every radiographer to be alert. The patient should not be subjected to unnecessary radiation from an unwanted examination. Rather, it is the radiographer's responsibility to check with the referring physician and report the patient's complaint.
480
48161 . While performing mobile radiography on a patient, you note that the requisition is for a chest image to check placement of a Swan- Ganz catheter. A Swan- Ganz catheter is a( n) 
482(A) pacemaker 
483(B) chest tube 
484(C) IV catheter 
485(D) urinary catheter
486 ------------------------------------------------ (C) A Swan- Ganz catheter is a specific type of IV catheter used to measure the pumping ability of the heart, to obtain pressure readings, and to introduce medications and IV fluids. A pacemaker is a device that is inserted under the patient's skin to regulate heart rate. Pacemakers may be permanent or temporary . Chest tubes are used to remove fluid or air from the pleural cavity. Any of these items may be identified on a chest radiograph, provided that the cassette is properly positioned and the correct exposure factors are employed. If the physician is interested in assessing the proper placement of a Swan- Ganz catheter , the lungs may have to be slightly overexposed to clearly delineate the proper placement of the tip of the Swan- Ganz catheter, which will overlap the denser cardiac silhouette. A urinary catheter will not appear on a chest radiograph.
487
48862 . Which of the following examinations require( s) restriction of a patient's diet? 
4891. Barium enema 
4902. Pyelogram 
4913. Metastatic survey 
492(A) 1 only 
493(B) 1 and 2 only
494(C) 1 and 3 only 
495(D) 2 and 3 only
496 ------------------------------------------------ (B) A patient who is having a BE generally is required to have a low-residue diet for 1 or 2 days, followed by cathartics and cleansing enemas prior to the examination. Any retained fecal material can simulate or obscure pathology. A patient who is scheduled for a pyelogram must have the preceding meal withheld to avoid the possibility of aspirating vomitus in case of an allergic reaction. A metastatic survey does not require the use of contrast media, and no patient preparation is necessary.
497
49863 . The radiographer must perform which of the following procedures prior to entering a contact isolation room with a mobile x-ray unit? 
4991. Put on gown and gloves only. 
5002. Put on gown, gloves, mask, and cap. 
5013. Clean the mobile x-ray unit. 
502(A) 1 only 
503(B) 2 only 
504(C) 1 and 3 only 
505(D) 2 and 3 only
506 ------------------------------------------------ (A) When performing bedside radiography in a contact isolation room, the radiographer should wear a gown and gloves. The IPs are prepared for the examination by placing a pillowcase over them to protect them from contamination. Whenever possible, one person should manipulate the mobile unit and remain "clean," whereas the other handles the patient. The mobile unit should be cleaned with a disinfectant on exiting the patient's room, not prior to entering.
507
50864 . Examples of nasogastric (NG) tubes include 1. Swan- Ganz 2. Salem-sump 3. Levin (A) 1 and 2 only (B) 1 and 3 only (C) 2 and 3 only (D) 1, 2, and 3
509 ------------------------------------------------ (C) The Levin and Salem-sump tubes are NG tubes used for gastric decompression. The Salem-sump tube is radiopaque and has a double lumen. One lumen is for gastric air compression, and the other is for removal of fluids. The Levin tube is a single-lumen tube that is used to prevent accumulation of intestinal liquids and gas during and following intestinal surgery. The Swan-Ganz IV catheter is advanced to the pulmonary artery and used to measure various heart pressures.
510
51165 . All the following are central venous lines except 
512(A) a Port-a-Cath 
513(B) a PICC 
514(C) a Swan- Ganz catheter 
515(D) a Salem-sump
516 ------------------------------------------------ (D) A catheter placed in a large vein is called a central venous line. It can be used to deliver frequent medications or nutrition or to monitor cardiac pressures. Catheters can vary in size and number of lumens depending on intended use. The Port-a-Cath is a totally implanted access port, and the peripherally inserted central catheter (PICC) is a peripherally inserted central catheter— they both permit long-term intravenous treatment. The Swan-Ganz catheter is advanced to the pulmonary artery and is used to measure the pumping ability of the heart, to obtain pressure readings, and to introduce medications and IV fluids. The Levin and Salem-sump tubes are NG tubes used for gastric decompression. The Salem-sump tube is radiopaque and has a double lumen. One lumen is for gastric air compression, and the other is for removal of fluids.
517
51866 . The most effective method of sterilization is 
519(A) dry heat 
520(B) moist heat 
521(C) pasteurization 
522(D) freezing
523 ------------------------------------------------ (B) The most effective method of sterilization is moist heat , using steam under pressure. This is known as autoclaving. Sterilization with dry heat requires higher temperatures for longer periods of time than sterilization with moist heat. Pasteurization is moderate heating with rapid cooling; it is used frequently in the commercial preparation of milk and alcoholic beverages such as wine and beer. It is not a form of sterilization. Freezing also can kill some microbes, but it is not a form of sterilization.
524
52567 . The condition in which pulmonary alveoli lose their elasticity and become permanently inflated, causing the patient to consciously exhale, is 
526(A) bronchial asthma 
527(B) bronchitis 
528(C) emphysema 
529(D) TB
530 ------------------------------------------------ (C) Emphysema is a progressive disorder caused by long-term irritation of the bronchial passages, such as by air pollution or cigarette smoking. Emphysema patients are unable to exhale normally because of loss of elasticity of alveolar walls. If emphysema patients receive oxygen , it is usually administered at a very slow flow rate because their respirations are controlled by the level of carbon dioxide in the blood.
531
53268 . Chest drainage systems should always be kept 
5331. below the level of the patient's chest 
5342. above the patient's chest 
5353. at the level of the patient's diaphragm 
536(A) 1 only 
537(B) 1 and 2 only 
538(C) 2 and 3 only 
539(D) 1, 2, and 3
540 ------------------------------------------------ (A) The chest drainage system unit always should be kept below the level of the patient's chest. Chest tubes are used to remove air, blood, or fluid from the pleural cavity. By draining fluid from the pleural cavity, a collapsed lung, or atelectasis, may be relieved. By relieving the pressure from air in the pleural cavity, a pneumothorax may be reduced. Radiographers must take care that the tubes of the chest drainage unit do not kink and do not get caught on IV poles or radiographic equipment. It is imperative that the unit remain below the level of the chest. The chest drainage system has several components. One component is a chamber that collects the draining fluid . Another component is the suction control chamber. A third component is the water-seal chamber, which prevents air from the atmosphere from entering the system . The last component is the water-seal venting chamber, which allows air to leave the system, thus preventing pressure buildup. In order for the unit to work properly, it must remain below the level of the chest.
541
54269 . What venous device can be used for a patient requiring IV injections at frequent or regular intervals? 
543(A) Butterfly needle 
544(B) Heparin lock 
545(C) IV infusion 
546(D) Hypodermic needle
547 ------------------------------------------------ (B) Another name for an intermittent injection port is a heparin lock. Heparin locks are used for patients who will require frequent or regular injections. An intravenous catheter is placed in the vein, and an external adapter with a diaphragm allows for repeated injections. This helps to prevent the formation of scarred, sclerotic veins as a result of frequent injections at the same site. Heparin locks provide more freedom than an IV infusion, which also allows for repeated access. Hypodermic needles usually are used for drawing blood or drawing up fluids, whereas a butterfly needle usually is used for venipuncture.
548
54970 . Which of the following statements is (are) true regarding the proper care of a patient with a tracheostomy? 
5501. Employ sterile technique if you must touch a tracheostomy for any reason. 
5512. Before you suction a tracheostomy, the patient should be well aerated. 
5523. Never suction for longer than 15 seconds, permitting the patient to rest in between. 
553(A) 1 and 2 only 
554(B) 1 and 3 only 
555(C) 2 and 3 only 
556(D) 1, 2, and 3
557 ------------------------------------------------ (D) All the statements in the question are true regarding the proper care of a patient with a tracheostomy. If a tracheostomy needs to be touched for any reason, sterile technique should be employed to avoid the possibility of infection. Patients with tracheostomies require frequent suction. This is usually not performed by the technologist, but radiographers may be called on to assist with suctioning, especially for patients who must be in the radiology department for lengthy procedures. Patients who are to be suctioned should be aerated beforehand (i.e., oxygen should be administered prior to suctioning). It is also important that patients be permitted to rest during suctioning. Never suction for longer than 15 seconds; check breath sounds with a stethoscope to ensure that the airway is clear. It is the radiographer's responsibility to check the work area and ensure that the suction is working and that ample ancillary supplies (i.e ., suction kit, catheters, and tubing) are available.
558
55971 . In which of the following situations should a radiographer wear protective eye gear (goggles)? 
5601. When performing an upper GI radiographic examination 
5612. When assisting the radiologist during an angiogram 
5623. When assisting the radiologist in a biopsy/ aspiration procedure 
563(A) 1 and 2 only 
564(B) 1 and 3 only
565(C) 2 and 3 only 
566(D) 1, 2, and 3
567 ------------------------------------------------ (C) It is recommended that a radiographer wear protective eye gear (goggles) during any procedure in which there might be splattering of blood or body fluids. This includes both angiography and biopsy/ aspiration procedures. This would not be expected during a routine upper GI examination.
568
56972 . In reviewing a patient's blood chemistry, which of the following blood urea nitrogen (BUN) ranges is considered normal? 
570(A) 0.6 to 1.5 mg/ 100 mL 
571(B) 4.5 to 6 mg/ 100 mL 
572(C) 8 to 25 mg/ 100 mL 
573(D) Up to 50 mg/ 100 mL
574 ------------------------------------------------ (C) The BUN level indicates the quantity of nitrogen in the blood in the form of urea. The normal concentration is 8 to 25 mg/ 100 mL. BUN and creatinine blood chemistry levels should be checked prior to beginning an IVU. An increase in the BUN level often indicates decreased renal function. Increased BUN and/ or creatinine levels may forecast an increased possibility of contrast media- induced renal effects and poor visualization of the renal collecting systems. The normal creatinine range is 0.6 to 1.5 mg/ 100 mL.
575
57673 . Particulate matter entering the respiratory bronchi can cause 
577(A) emphysema 
578(B) empyema 
579(C) pneumothorax 
580(D) pneumoconiosis
581 ------------------------------------------------ (D) Pneumoconiosis is a condition of the lungs characterized by particulate matter having been deposited in lung tissue; it sometimes results in emphysema. Overdistension of the alveoli with air is emphysema. The condition is often a result of many years of smoking and is characterized by dyspnea, especially when recumbent. Empyema is pus in the thoracic cavity; pneumothorax is air or gas in the pleural cavity.
582
58374 . All the following are forms of mechanical obstruction seen in neonates or infants except 
584(A) paralytic ileus 
585(B) meconium ileus 
586(C) volvulus 
587(D) intussusception
588 ------------------------------------------------ (A) Volvulus and intussusception both involve a mechanical "closure" or obstruction of the intestinal lumen by a change in the continuous pathway of the GI tract— volvulus by a twisting of the bowel on itself causing obstruction and intussusception by "telescoping" of the bowel causing obstruction. Meconium ileus is another form of mechanical obstruction where meconium (first feces of a newborn) becomes hardened and impacted, causing obstruction. Paralytic (or adynamic) ileus, however, is an obstruction caused by loss of peristaltic movement of the intestine.
589
59075 . The pain experienced by an individual whose coronary arteries are not conveying sufficient blood to the heart is called 
591(A) tachycardia 
592(B) bradycardia 
593(C) angina pectoris 
594(D) syncope
595 ------------------------------------------------ (C) An individual whose coronary arteries are not carrying enough blood to the heart muscle (myocardium) as a result of partial or complete blockage of a cardiac vessel experiences crushing pain in the chest, frequently radiating to the left jaw and arm. This is termed angina pectoris. It may be relieved by the drug nitroglycerin, which dilates the coronary arteries, thus facilitating circulation. Tachycardia refers to rapid heart rate, and bradycardia, to slow heart rate. Syncope is fainting.
596
59776 . A MRI procedure is contraindicated for a patient who has 
598(A) a herniated disk 
599(B) aneurysm clips 
600(C) dental fillings 
601(D) subdural bleeding
602 ------------------------------------------------ (B) The presence of aneurysm clips is contraindication for magnetic resonance imaging (MRI); even a slight shift can cause damage. MRI can be performed for a herniated disk and subdural bleeding. Dental fillings do not contraindicate MRI.
603
60477 . An inanimate object that has been in contact with an infectious microorganism is termed a 
605(A) vector 
606(B) fomite 
607(C) host 
608(D) reservoir
609 ------------------------------------------------ (B) A fomite is an inanimate object that has been in contact with an infectious microorganism. A reservoir is a site where an infectious organism can remain alive and from which transmission can occur. Although an inanimate object can be a reservoir for infection, living objects (such as humans) also can be reservoirs. For infection to spread, there must be a host environment. Although an inanimate object may serve as a temporary host where microbes can grow, microbes flourish on and in the human host, where there are plenty of body fluids and tissues to nourish and feed the microbes. A vector is an animal host of an infectious organism that transmits the infection via bite or sting.
610
61178 . The advantages of using nonionic, water-soluble contrast media include 
6121. cost-containment benefits 
6132. low toxicity 
6143. fewer adverse reactions 
615(A) 1 only 
616(B) 1 and 2 only 
617(C) 2 and 3 only
618(D) 1, 2, and 3
619 ------------------------------------------------ (C) The relatively low osmolality and nonionic, water-soluble contrast media available to radiology departments have outstanding advantages, especially for patients with a history of allergic reaction. They were used originally for intrathecal injections (myelography ), but they were quickly accepted for intravascular injections as well. Side effects and allergic reactions are less likely and less severe with these media. Their one very significant disadvantage is their high cost compared with that of ionic contrast media.
620
62179 . A radiographer should recognize that geronto-logic patients often have undergone physical changes that include loss of 
6221. muscle mass 
6232. bone calcium 
6243. mental alertness 
625(A) 1 only 
626(B) 1 and 2 only 
627(C) 1 and 3 only 
628(D) 1, 2, and 3
629 ------------------------------------------------ (B) Gerontology, or geriatrics, is the study of the elderly. Although bone demineralization and loss of muscle mass occur to a greater or lesser degree in most elderly individuals, the radiographer must not assume that all gerontologic patients are hard of hearing, clumsy, or not mentally alert . Today, many elderly people remain very active, staying mentally and physically agile well into their so-called golden years. The radiographer must keep this in mind as he or she provides age-specific care to the gerontologic patient.
630
63180 . Which of the following statements is (are) true regarding a two-member team performing mobile radiography on a patient with MRSA precautions? 
6321. One radiographer remains "clean"—that is, he or she has no physical contact with the patient. 
6332. The radiographer who positions the mobile unit also makes the exposure. 
6343. The radiographer who positions the cassette also retrieves the cassette and removes it from its plastic protective cover. 
635(A) 1 and 2 only 
636(B) 1 and 3 only 
637(C) 2 and 3 only 
638(D) 1, 2, and 3
639 ------------------------------------------------ (A) When a two-member team of radiographers is performing mobile radiography on a patient with contact precautions, such as an MRSA patient, one radiographer remains "clean"— that is, he or she has no physical contact with the patient. The clean radiographer will position the mobile unit and make the exposure. The other member of the team will position the cassette and retrieve the cassette. As the two radiographers fold down the cassette's protective plastic cover, the "clean" radiographer will remove the cassette from the plastic. Both radiographers should be protected with gowns, gloves, and masks if the patient is on contact precautions. In addition , after the examination is completed, the mobile unit should be cleaned with a disinfectant. Conditions requiring the use of contact precautions also include hepatitis A and varicella infection.
640
64181 . Symptoms associated with a respiratory reaction to contrast media include 
6421. sneezing 
6432. hoarseness 
6443. wheezing 
645(A) 1 and 2 only 
646(B) 1 and 3 only 
647(C) 2 and 3 only 
648(D) 1, 2, and 3
649 ------------------------------------------------ (D) All these symptoms are related to a respiratory reaction. There also may be dyspnea, asthma attack, or cyanosis. The patient who has received contrast media should be watched closely. If any symptoms arise, the radiologist should be notified immediately.
650
65182 . While in your care for a radiologic procedure, a patient asks to see his chart. Which of the following is the appropriate response? 
652(A) Inform the patient that the chart is for health care providers to view, not for the patient. 
653(B) Inform the patient that you do not know where the chart is. 
654(C) Inform the patient that he has the right to see his chart but that he should request to view it with his physician so that it is interpreted properly. 
655(D) Give the patient the chart and leave him alone for a few minutes to review it.
656 ------------------------------------------------ (C) If a patient in your care asks to see his or her chart , the appropriate response is to refer the patient to his or her physician. A patient does have the right to review his or her own medical record; however, the patient should do so in the presence of the physician so that the patient does not misinterpret the information and so that the physician can address concerns or answer questions . It is not appropriate to hand over the chart to a patient, nor is it appropriate to deceive the patient into believing that the chart is not available for viewing or that the patient has no right to review the chart.
657
65883 . Skin discoloration owing to cyanosis may be observed in the 
6591. gums 
6602. earlobes 
6613. tongue 
662(A) 1 only 
663(B) 1 and 2 only 
664(C) 3 only 
665(D) 1, 2, and 3
666 ------------------------------------------------ (B) Cyanosis is a condition resulting from a deficiency of oxygen circulating in the blood. It is characterized by bluish discoloration of the gums, nailbeds, earlobes, and the area around the mouth. Cyanosis may be accompanied by labored breathing or other types of respiratory distress.
667
66884 . Diseases spread by direct or close contact include 
6691. MRSA 
6702. Conjunctivitis 
6713. Hepatitis A 
672(A) 1 only 
673(B) 1 and 2 only 
674(C) 2 and 3 only 
675(D) 1, 2, and 3
676 ------------------------------------------------ (D) Category-specific isolations have been replaced by transmission-based precautions: airborne, droplet, and contact. Under these guidelines, some conditions or diseases can fall into more than one category. Any diseases spread by direct or close contact, such as MRSA, conjunctivitis, and hepatitis A, require contact precautions. Contact precautions require a private patient room and the use of gloves, masks, and gowns for anyone coming in direct contact with the infected individual or his or her environment. Airborne precautions are employed with patients suspected or known to be infected with tubercle bacillus (TB), chickenpox (varicella), or measles (rubeola). Airborne precautions require that the patient wear a mask to avoid the spread of bronchial secretions or other pathogens during coughing. If the patient is unable or unwilling to wear a mask, the radiographer must wear one. The radiographer should wear gloves, but a gown is required only if flagrant contamination is likely. Patients under airborne precautions require a private, specially ventilated (negative-pressure) room. A private room is also indicated for all patients on droplet precautions, that is, with diseases transmitted via large droplets expelled from the patient while speaking, sneezing, or coughing. The pathogenic droplets can infect others when they come in contact with mouth or nasal mucosa or conjunctiva. Rubella (" German measles"), mumps, and influenza are among the diseases spread by droplet contact; a private room is required for the patient, and health care practitioners should use gowns and gloves.
677
67885 . You receive an ambulatory patient for a GI series . As the patient is being seated on the x-ray table, he tells you he feels faint. You should 
6791. lay the patient down on the x-ray table 
6802. elevate the patient's legs or place the table slightly Trendelenburg 
6813. leave quickly and call for help 
682(A) 1 only 
683(B) 1 and 2 only 
684(C) 1 and 3 only 
685(D) 1, 2, and 3
686 ------------------------------------------------ (B) A patient who has been NPO since midnight or who is anxious, frightened, or in pain may suffer an episode of syncope (fainting) on exertion. The patient should be helped to a recumbent position with feet elevated to increase blood flow to the head. A patient who feels like fainting should never be left alone.
687
68886 . The medical term for hives is 
689(A) vertigo 
690(B) epistaxis 
691(C) urticaria 
692(D) aura
693 ------------------------------------------------ (C) Urticaria is a vascular reaction resulting in dilated capillaries and edema and causing the patient to break out in hives. The medical term for nosebleed is epistaxis. Vertigo refers to a feeling of "whirling" or a sensation that the room is spinning. Some possible causes of vertigo include inner ear infection and acoustic neuroma. An aura may be classified as either a feeling or a sensory response (such as flashing lights, tasting metal, or smelling coffee) that precedes an episode such as a seizure or a migraine headache.
694
69587 . Blood pressure is measured in units of 
696(A) millimeters of mercury (mm Hg) 
697(B) beats per minute 
698(C) degrees Fahrenheit (° F) 
699(D) liters per minute (L/ min)
700 ------------------------------------------------ (A) Blood pressure is measured in millimeters of mercury ( mmHg ). Heart rate, or pulse , is measured in units of beats per minute. Temperature is measured in degrees Fahrenheit (° F). Oxygen delivery is measured in units of liters per minute (L/ min). Table 1- 1 outlines the normal ranges for vital signs in healthy adults.
701
70288 . Which blood vessels are best suited for determination of pulse rate? 
703(A) Superficial arteries 
704(B) Deep arteries 
705(C) Superficial veins 
706(D) Deep veins
707 ------------------------------------------------ (A) Superficial arteries are best suited for determination of pulse rate. The five most easily palpated pulse points are the radial, carotid, temporal, femoral, and popliteal pulses. The radial pulse is used most frequently. The apical pulse, at the apex of the heart, is most accurate and can be determined with the use of a stethoscope.
708
70989 . Which ethical principle is related to sincerity and truthfulness? 
710(A) Beneficence 
711(B) Autonomy 
712(C) Veracity 
713(D) Fidelity
714 ------------------------------------------------ (C) Veracity ( i.e., sincerity) is not only telling the truth but also not practicing deception. Autonomy is the ethical principle that is related to the theory that patients have the right to decide what will or will not be done to them. Beneficence is related to the idea of doing good and being kind. Fidelity is faithfulness and loyalty.
715
71690 . The medical term for congenital clubfoot is 
717(A) coxa plana 
718(B) osteochondritis 
719(C) talipes 
720(D) muscular dystrophy
721 ------------------------------------------------ (C) Talipes is the term used to describe congenital clubfoot. There are several types of talipes, generally characterized by a deformed talus and a shortened Achilles tendon, giving the foot a clubfoot appearance. Osteochondritis (Osgood-Schlatter disease) is a painful incomplete separation of the tibial tuberosity from the tibial shaft. It is often seen in active adolescent boys. Coxa plana (Legg- Calvé-Perthes disease) is ischemic necrosis leading to flattening of the femoral head. Muscular dystrophy is a congenital disorder characterized by wasting of skeletal muscles.
722
72391 . In what order should the following examinations be performed? 
7241. Upper GI series 
7252. IVU 
7263. BE 
727(A) 3, 1, 2 
728(B) 1, 3, 2
729(C) 2, 1, 3 
730(D) 2, 3, 1
731 ------------------------------------------------ (D) When scheduling patient examinations, it is important to avoid the possibility of residual contrast medium covering areas that will be of interest on later examinations. The IVU [also referred to as an intravenous pyelogram (IVP)] should be scheduled first because the contrast medium used is excreted rapidly. The BE should be scheduled next. Finally, the upper GI series is scheduled. There should not be enough barium remaining from the previous BE to interfere with the examination of the stomach or duodenum, although a preliminary scout image should be taken in each case.
732
73392 . Hypochlorite bleach (Clorox) and Lysol are examples of 
734(A) antiseptics 
735(B) bacteriostatics 
736(C) antifungal agents 
737(D) disinfectants
738 ------------------------------------------------ (D) Hypochlorite bleach (Clorox) and Lysol are examples of disinfectants. Disinfectants are used in radiology departments to clean equipment and to remove microorganisms from areas such as radiographic tables. Antiseptics are also used to stop the growth of microorganisms , but they are often applied to the skin, not to radiographic equipment. Antifungal medications can be administered systemically or topically to treat or prevent fungal infections. Antibacterial medications (bacteriostatics) also can be administered systemically or externally. Tetracycline is a systemic antibacterial medication.
739
74093 . The condition that allows blood to shunt between the right and left ventricles is called 
741(A) patent ductus arteriosus 
742(B) coarctation of the aorta 
743(C) atrial septal defect 
744(D) ventricular septal defect
745 ------------------------------------------------ (D) Ventricular septal defect is a congenital heart condition characterized by a hole in the interventricular septum that allows oxygenated and unoxygenated blood to mix. Some interventricular septal defects are small and close spontaneously; others require surgery. Coarctation of the aorta is a narrowing or constriction of the aorta. Atrial septal defect is a small hole (the remnant of the fetal foramen ovale) in the interatrial septum. It usually closes spontaneously in the first months of life; if it persists or is unusually large, surgical repair is necessary. The ductus arteriosus is a short fetal blood vessel connecting the aorta and pulmonary artery that usually closes within 10 to 15 hours after birth. A patent ductus arteriosus is one that persists and requires surgical closure.
746
74794 . Logrolling is a method of moving patients having suspected 
748(A) head injury 
749(B) spinal injury 
750(C) bowel obstruction 
751(D) extremity fracture
752 ------------------------------------------------ (B) Patients arriving at the emergency department (ED) with suspected spinal injury should not be moved. Anteroposterior (AP) and horizontal lateral projections of the suspected area should be evaluated and a decision made about the advisability of further images. For a lateral projection, the patient should be moved along one plane, that is, rolled like a log. It is imperative that twisting motions be avoided.
753
75495 . The cycle of infection includes which of the following components? 
7551. Reservoir of infection 
7562. Susceptible host 
7573. Means of transmission 
758(A) 1 only 
759(B) 1 and 2 only 
760(C) 2 and 3 only 
761(D) 1, 2, and 3
762 ------------------------------------------------ (D) The cycle of infection includes four components: a susceptible host , a reservoir of infection , a pathogenic organism, and a means of transmission . Pathogenic organisms are microscopic and include bacteria, fungi, and viruses. The reservoir of infection is the environment in which the microorganism thrives; this can be the human body. A susceptible host may have reduced resistance to infection. The means of transmission is either direct (i.e., touch) or indirect (i.e., vector, fomite, or airborne).
763
76496 . The act of inspiration will cause elevation of the 
7651. sternum 
7662. ribs 
7673. diaphragm 
768(A) 1 only 
769(B) 1 and 2 only 
770(C) 2 and 3 only 
771(D) 1, 2, and 3
772 ------------------------------------------------ (B) The diaphragm is the major muscle of respiration. On inspiration/ inhalation, the diaphragm and abdominal viscera are depressed, enabling filling and expansion of the lungs, accompanied by upward movement of the sternum and ribs. During expiration/ exhalation, air leaves the lungs, and they deflate while the diaphragm relaxes and moves to a more superior position along with the abdominal viscera. As the diaphragm relaxes and moves up, the sternum and ribs move inferiorly.
773
77497 . A radiologic technologist can be found guilty of a tort in which of the following situations? 
7751. Failure to shield a patient of childbearing age from unnecessary radiation 
7762. Performing an examination on a patient who has refused the examination 
7773. Discussing a patient's condition with a third party 
778(A) 1 only 
779(B) 1 and 2 only 
780(C) 2 and 3 only 
781(D) 1, 2, and 3
782 ------------------------------------------------ (D) A tort is an intentional or unintentional act that involves personal injury or damage to a patient. Allowing a patient to be exposed to unnecessary radiation, either by neglecting to shield the patient or by performing an unwanted examination, would be considered a tort, and the radiographer would be legally accountable. Discussing a patient's condition with a third party undoubtedly would be considered a serious intentional tort.
783
78498 . Guidelines for cleaning contaminated objects or surfaces include which of the following? 
7851. Clean from the least contaminated to the most contaminated areas. 
7862. Clean in a circular motion, starting from the center and working outward. 
7873. Clean from the top down. 
788(A) 1 only 
789(B) 1 and 2 only 
790(C) 1 and 3 only 
791(D) 1, 2, and 3
792 ------------------------------------------------ (C) Because hospitals are the refuge of the sick, they can also be places of disease transmission unless proper infection control guidelines are followed. When cleaning contaminated objects or surfaces such as the radiographic table, it is important to clean from the least contaminated to the most contaminated area and from the top down. Soiled gowns and linens should be folded from the outside in and disposed of properly. When the patient's skin is being prepared for surgery, it is often cleaned in circular motion starting from the center and working outward; however, this motion is not used for objects or surfaces.
793
79499 . If a radiographer performed a lumbar spine examination on a patient who was supposed to have an elbow examination, which of the following charges may be brought against the radiographer? 
795(A) Assault 
796(B) Battery 
797(C) False imprisonment 
798(D) Defamation
799 ------------------------------------------------ (B) A radiographer who performs the wrong examination on a patient may be charged with battery. Battery refers to the unlawful laying of hands on a patient. The radiographer also could be charged with battery if a patient is moved about roughly or touched in a manner that is inappropriate or without the patient's consent. Assault is the threat of touching or laying hands on someone. If a patient feels threatened by a practitioner, either because of the tone or pitch of the practitioner's voice or because the practitioner uses words that are threatening, the practitioner can be accused of assault. False imprisonment may be considered if a patient is ignored after stating that she no longer wishes to continue with the procedure or if restraining devices are used improperly or used without a physician's order. The accusation of defamation can be upheld when patient confidentiality is not respected and, as a result, the patient suffers embarrassment or mockery.
800
801100 . Types of inflammatory bowel disease include 
8021. ulcerative colitis 
8032. Crohn's disease 
8043. intussusception 
805(A) 1 only 
806(B) 1 and 2 only 
807(C) 2 and 3 only 
808(D) 1, 2, and 3
809 ------------------------------------------------ (B) The two most common types of chronic inflammation of the intestines are ulcerative colitis and Crohn's disease. The latter can attack any part of the GI tract and extends through all layers of the intestinal wall (therefore the possibility of forming fistulous tracks to contiguous structures). Ulcerative colitis attacks only the large bowel and only the mucosal layer of the intestinal wall. Curiously, cigarette smoking increases the risk for Crohn's disease and decreases the risk for ulcerative colitis. Intussusception is an obstructive disorder.
810
811101 . Which of the following statements would be true regarding tracheostomy patients? 
8121. Tracheostomy patients have difficulty speaking. 
8132. A routine chest x-ray requires the tracheostomy tubing to be rotated out of view. 
8143. Audible rattling sounds indicate a need for suction. 
815(A) 1 only 
816(B) 1 and 2 only 
817(C) 1 and 3 only 
818(D) 1, 2, and 3
819 ------------------------------------------------ (C) The tracheostomy patient will have difficulty speaking as a result of redirection of the air past the vocal cords. Gurgling or rattling sounds coming from the trachea indicate an excess accumulation of secretions, requiring suction with sterile catheters. Any rotation or movement of the tracheostomy tube may cause the tube to become dislodged, and an obstructed airway could result.
820
821102 . When caring for a patient with an IV line, the radiographer should keep the medication 
822(A) 18 to 20 inches above the level of the vein 
823(B) 18 to 20 inches below the level of the vein 
824(C) 28 to 30 inches above the level of the vein 
825(D) 28 to 30 inches below the level of the vein
826 ------------------------------------------------ (A) It is generally recommended that the IV bottle/ bag be kept 18 to 20 inches above the level of the vein. If the container is too high, the pressure of the IV fluid can cause it to pass through the vein into surrounding tissues , causing a painful and potentially harmful condition. If the IV container is too low, blood may return through the needle into the tubing, form a clot, and obstruct the flow of IV fluid.
827
828103 . Diseases that require droplet precautions include 
8291. rubella 
8302. mumps 
8313. influenza
832(A) 1 only 
833(B) 1 and 2 only 
834(C) 2 and 3 only 
835(D) 1, 2, and 3
836 ------------------------------------------------ (D) A private room is indicated for all patients on droplet precaution; that is, diseases transmitted via large droplets expelled from the patient while speaking, sneezing, or coughing. The pathogenic droplets can infect others when they come in contact with mouth or nasal mucosa or conjunctiva. Rubella (" German measles"), mumps, and influenza are among the diseases spread by droplet contact; a private room is required for the patient , and health care practitioners must wear a regular (string) mask to enter a droplet precautions isolation room.
837
838104 . Protective or "reverse" isolation is required in which of the following conditions? 
8391. TB 
8402. Burns 
8413. Leukemia 
842(A) 1 only 
843(B) 1 and 2 only 
844(C) 2 and 3 only 
845(D) 1, 2, and 3
846 ------------------------------------------------ (C) Protective or "reverse" isolation is used to keep the susceptible patient from becoming infected. Patients who have suffered burns have lost a very important means of protection, their skin, and therefore have increased susceptibility to bacterial invasion. Patients whose immune systems are depressed have lost the ability to combat infection and hence are more susceptible to infection. Active TB requires airborne precautions, not protective isolation.
847
848105 . When a GI series has been requested on a patient with a suspected perforated ulcer, the type of contrast medium that should be used is 
849(A) a thin barium sulfate suspension 
850(B) a thick barium sulfate suspension 
851(C) water-soluble iodinated media 
852(D) oil-based iodinated media
853 ------------------------------------------------ (C) Whenever a perforation of the GI tract is suspected, a water-soluble contrast agent (such as Gastrografin or oral Hypaque) should be used because it is easily absorbed from within the peritoneal cavity . Leakage of barium sulfate into the peritoneal cavity can have serious consequences. Water-soluble contrast agents also may be used in place of barium sulfate when the possibility of barium impaction exists. Oil-based contrast agents are used rarely today.
854
855106 . Nitroglycerin is used 
856(A) to relieve pain from angina pectoris 
857(B) to prevent a heart attack 
858(C) as a vasoconstrictor 
859(D) to increase blood pressure
860 ------------------------------------------------ (A) Angina pectoris is a crushing chest pain caused by a circulatory disturbance of the coronary arteries. Nitroglycerin is used to dilate blood vessels (vasodilation) and decrease blood pressure in the treatment of pain from angina pectoris. Nitroglycerin usually is given sublingually and thus is absorbed directly into the bloodstream.
861
862107 . A patient experiencing an episode of syncope should be placed in which of the following positions? 
863(A) Dorsal recumbent with head elevated 
864(B) Dorsal recumbent with feet elevated 
865(C) Lateral recumbent 
866(D) Seated with feet supported
867 ------------------------------------------------ (B) Syncope, or fainting, is the result of a drop in blood pressure caused by insufficient blood (oxygen) flow to the brain. The patient should be helped into a dorsal recumbent position with feet elevated to facilitate blood flow to the brain.
868
869108 . The diameter of a needle's lumen is referred to as its 
870(A) bevel 
871(B) gauge 
872(C) hub 
873(D) length
874 ------------------------------------------------ (B) The diameter of a needle is the needle's gauge. The higher the gauge number, the smaller is the diameter and the thinner is the needle. For example, a very tiny-gauge needle (25 gauge) may be used on a pediatric patient for an IV injection , whereas a large-gauge needle (16 gauge) may be used for donating blood. The hub of a needle is the portion of the needle that attaches to a syringe. The length of the needle varies depending on its use. A longer needle is needed for intramuscular injections, whereas a shorter needle is used for subcutaneous injection. The bevel of the needle is the slanted tip of the needle. For IV injections, the bevel always should face up.
875
876109 . A patient in a recumbent position with the head lower than the feet is said to be in which of the following positions? 
877(A) Trendelenburg 
878(B) Fowler 
879(C) Sims 
880(D) Stenver
881 ------------------------------------------------ (A) The patient is said to be in the Trendelenburg position when the head is positioned lower than the feet. This position is helpful in several radiographic procedures, such as separating redundant bowel loops and demonstration of hiatal hernias. It is also used in treating shock. In the Fowler position, the head is higher than the feet. The Sims position is the left posterior oblique (LPO) position with the right leg flexed up for insertion of the enema tip. The Stenver position is a radiographic position for radiographing the mastoids.
882
883110 . The normal average rate of respiration for a healthy adult patient is 
884(A) 5 to 7 breaths/ min 
885(B) 8 to 12 breaths/ min 
886(C) 12 to 20 breaths/ min 
887(D) 20 to 30 breaths/ min
888 ------------------------------------------------ (C) The normal average rate of respiration for a healthy adult patient is between 12 and 20 breaths /min. For children, the rate is higher, averaging between 20 and 30 breaths/ min. In addition to monitoring the respiratory rate , it is also important to monitor the depth (shallow or labored) and pattern (regularity) of respiration. A respiratory rate greater than 20 breaths/ min in an adult would be considered tachypnea.
889
890111 . Which of the following is a vasopressor and may be used for an anaphylactic reaction or a cardiac arrest? 
891(A) Nitroglycerin 
892(B) Epinephrine 
893(C) Hydrocortisone 
894(D) Digitoxin
895 ------------------------------------------------ (B) Epinephrine (Adrenalin) is the vasopressor used to treat an anaphylactic reaction or cardiac arrest. Nitroglycerin is a vasodilator. Hydrocortisone is a steroid that may be used to treat bronchial asthma, allergic reactions, and inflammatory reactions. Digitoxin is used to treat cardiac fibrillation.
896
897112 . Examples of means by which infectious microorganisms can be transmitted via indirect contact include 
8981. a fomite 
8992. a vector 
9003. nasal or oral secretions 
901(A) 1 only 
902(B) 1 and 2 only 
903(C) 2 and 3 only 
904(D) 1, 2, and 3
905 ------------------------------------------------ (B) Infectious microorganisms can be transmitted from patients to other patients or to health care workers and from health care workers to patients. They are transmitted by means of either direct or indirect contact. Direct contact involves touch. Diseases transmitted by direct contact include skin infections such as boils and sexually transmitted diseases such as syphilis and AIDS. Direct contact with droplets of nasal or oral secretions from a sneeze or cough is referred to as droplet contact. Indirect contact involves transmission of microorganisms via airborne contamination, fomites, and vectors. Pathogenic microorganisms expelled from the respiratory tract through the mouth or nose can be carried as evaporated droplets through the air or dust and settle on clothing, utensils, or food. Patients with respiratory tract infections or disease transported to the radiology department therefore should wear a mask to prevent such transmission during a cough or sneeze; it is not necessary for the health care worker to wear a mask (as long as the patient does). Many microorganisms can remain infectious while awaiting transmission to another host. A contaminated inanimate object such as a food utensil , doorknob, or IV pole is referred to as a fomite. A vector is an insect or animal carrier of infectious organisms, such as a rabid animal, a mosquito that carries malaria, or a tick that carries Lyme disease. They can transmit disease through either direct or indirect contact.
906
907113 . All the following rules regarding proper hand washing technique are correct except 
908(A) keep hands and forearms lower than elbows 
909(B) use paper towels to turn water on 
910(C) avoid using hand lotions whenever possible 
911(D) carefully wash all surfaces and between fingers
912 ------------------------------------------------ (C) Frequent and correct hand hygiene is an essential part of medical asepsis; it is the best method for avoiding the spread of microorganisms. If the faucet cannot be operated with the knee or a foot pedal, it should be opened and closed using paper towels. Care should be taken to wash all surfaces of the hand and between the fingers thoroughly. The hands and forearms always should be kept below the elbows. Hand lotions should be used frequently to keep hands from chapping. Unbroken skin prevents the entry of microorganisms; dry, cracked skin breaks down that defense and permits the entry of microorganisms.
913
914114 . The following instructions should be given to a patient following a barium sulfate contrast examination: 
9151. Increase fluid and fiber intake for several days. 
9162. Changes in stool color will occur until all barium has been evacuated. 
9173. Contact a physician if no bowel movement occurs in 24 hours. 
918(A) 1 only 
919(B) 2 only 
920(C) 1 and 3 only 
921(D) 1, 2, and 3
922 ------------------------------------------------ (D) Physicians often prescribe a mild laxative to aid in the elimination of barium sulfate. If a laxative is not given, the patient should be instructed to increase dietary fluid and fiber and to monitor bowel movements (the patient should have at least one within 24 hours). Patients should also be aware of the white appearance of their stool that will be present until all barium is expelled.
923
924115 . The medical abbreviation meaning "after meals" is 
925(A) tid 
926(B) qid 
927(C) qh 
928(D) pc
929 ------------------------------------------------ (D) The medical abbreviation pc means "after meals." "Three times a day" is indicated by the abbreviation tid. The abbreviation qid means "four times a day." "Every hour" is represented by qh.
930
931116 . Symptoms of inadequate oxygen supply include 
9321. dyspnea 
9332. cyanosis 
9343. retraction of intercostal spaces 
935(A) 1 only 
936(B) 1 and 2 only 
937(C) 2 and 3 only 
938(D) 1, 2, and 3
939 ------------------------------------------------ (D) Oxygen is taken into the body and supplied to the blood to be delivered to all body tissues. Any tissue( s) lacking in or devoid of an adequate blood supply can suffer permanent damage or die. Oxygen may be required in cases of severe anemia, pneumonia, pulmonary edema, and shock. Symptoms of inadequate oxygen supply include dyspnea, cyanosis, diaphoresis, retraction of intercostal spaces, dilated nostrils, and distension of the veins of the neck. The patient who experiences any of these symptoms will be very anxious and must not be left unattended. The radiographer must call for help, assist the patient to a sitting or semi-Fowler position (the recumbent position makes breathing more difficult), and have oxygen and emergency drugs available.
940
941117 . A patient whose systolic blood pressure is consistently greater than 140 mm Hg usually is considered 
942(A) hypertensive 
943(B) hypotensive 
944(C) average/ normal 
945(D) baseline
946 ------------------------------------------------ (A) Systolic blood pressure describes the pressure during contraction of the heart. It is expressed as the top (left) number when recording blood pressure. Diastolic blood pressure is the reading during relaxation of the heart and is placed on the bottom (right) when recording blood pressure. A patient is considered hypertensive when the systolic pressure is consistently above 140 mmHg and hypotensive when the systolic pressure is lower than 90 mm Hg.
947
948118 . In which of the following conditions is a double-contrast BE essential for demonstration of the condition? 
9491. Polyps 
9502. Colitis 
9513. Diverticulosis 
952(A) 1 only 
953(B) 1 and 2 only 
954(C) 1 and 3 only 
955(D) 1, 2, and 3
956 ------------------------------------------------ (B) Double-contrast studies of the large bowel are particularly useful for demonstration of the bowel wall and anything projecting into it , for example, polyps. Polyps are projections of the bowel wall mucous membrane into the bowel lumen. Colitis is inflammation of the large bowel, often associated with ulcerations of the mucosal wall. A single- contrast study most likely would obliterate these mucosal conditions, but coating of the bowel mucosa with barium and subsequent filling of the bowel with air (double contrast) provide optimal delineation. Single-contrast studies will demonstrate projections/ outpouchings from the intestinal wall such as diverticulitis.
957
958119 . When a radiographer is obtaining a patient history, both subjective and objective data should be obtained. An example of subjective data is that 
959(A) the patient appears to have a productive cough 
960(B) the patient has a blood pressure of 130/ 95 mm Hg 
961(C) the patient states that she experiences extreme pain in the upright position 
962(D) the patient has a palpable mass in the right upper quadrant of the left breast
963 ------------------------------------------------ (C) Obtaining a complete and accurate history from the patient for the radiologist is an important aspect of a radiographer's job. Both subjective and objective data should be collected. Objective data include signs and symptoms that can be observed, such as a cough, a lump, or elevated blood pressure. Subjective data relate to what the patient feels and to what extent. A patient may experience pain, but is it mild or severe? Is it localized or general? Does the pain increase or decrease under different circumstances? A radiographer should explore this with the patient and document the information on the requisition for the radiologist.
964
965120 . Symptoms of impending diabetic coma include 
9661. increased urination 
9672. sweet-smelling breath 
9683. extreme thirst 
969(A) 1 and 2 only 
970(B) 1 and 3 only 
971(C) 2 and 3 only 
972(D) 1, 2, and 3
973 ------------------------------------------------ (D) When a diabetic patient misses an insulin injection, the body loses its ability to metabolize glucose, and ketoacidosis can occur. If this is not corrected quickly, the patient may become comatose. Symptoms of impending coma include increased urination, sweet (fruity) breath, and extreme thirst. Other symptoms are weakness and nausea.
974
975121 . Diseases that require contact precautions include 
9761. MRSA 
9772. Clostridium difficile (C-diff) 
9783. TB 
979(A) 1 only 
980(B) 1 and 2 only 
981(C) 2 and 3 only 
982(D) 1, 2, and 3
983 ------------------------------------------------ (B) Any disease spread by direct or close contact, such as MRSA and Clostridium difficile (C-diff), and some wounds require contact precautions. Contact precaution procedures require a private patient room and the use of gloves and gowns for anyone coming in direct contact with the infected individual or the infected person's environment. Some facilities require health care workers to wear a mask when caring for a patient with MRSA infection.
984
985122 . Which of the following is (are) symptom( s) of shock? 
9861. Pallor and weakness 
9872. Increased pulse 
9883. Fever 
989(A) 1 only 
990(B) 1 and 2 only 
991(C) 1 and 3 only 
992(D) 1, 2, and 3
993 ------------------------------------------------ (B) A patient who is going into shock may exhibit pallor and weakness, a significant drop in blood pressure, and an increased pulse. The patient may also experience apprehension and restlessness and may have cool, clammy skin. A radiographer recognizing these symptoms should call them to the physician's attention immediately. Fever is not associated with shock.
994
995123 . Increased pain threshold, breakdown of skin, and atrophy of fat pads and sweat glands are all important considerations when working with which of the following groups of patients? 
996(A) Infants 
997(B) Children 
998(C) Adolescents 
999(D) Geriatric patients
1000 ------------------------------------------------ (D) Increased pain threshold, breakdown of skin, and atrophy of fat pads and sweat glands are all important considerations when working with geriatric patients. Many changes occur as our bodies age. Although muscle is replaced with fat, the amount of subcutaneous fat is decreased, and the skin atrophies. Therefore, the geriatric patient requires extragentle treatment. A mattress pad should always be placed on the radiographic table to help prevent skin injury or abrasions . If tape is required, paper tape should be used instead of adhesive tape. Geriatric patients are also more sensitive to hypothermia because of the breakdown of the sweat glands and always should be kept covered both to preserve modesty and for extra warmth. Loss of sensation in the skin increases pain tolerance, so the geriatric patient may not be aware of excessive stress on bony prominences such as the elbow, wrist, coccyx, and ankles.
1001
1002124 . The practice that is used to retard the growth of pathogenic bacteria is termed 
1003(A) antisepsis 
1004(B) disinfection 
1005(C) sterilization 
1006(D) medical asepsis
1007 ------------------------------------------------ (A) Antisepsis is the practice that retards the growth of pathogenic bacteria. Medical asepsis refers to the destruction of pathogenic microorganisms through the process of disinfection. Examples of disinfectants include hydrogen peroxide, chlorine, and boric acid. Surgical asepsis (i.e., sterilization ) refers to the removal of all microorganisms and their spores (reproductive cells) and is practiced in the surgical suite. Health care practitioners must practice medical asepsis at all times.
1008
1009125 . The usual patient preparation for an upper GI examination is 
1010(A) nothing by mouth (NPO) 8 hours before the examination 
1011(B) light breakfast only on the morning of the examination 
1012(C) clear fluids only on the morning of the examination 
1013(D) 2 oz of castor oil and enemas until clear
1014 ------------------------------------------------ (A) To obtain a diagnostic examination of the stomach, it must first be empty. The usual preparation is NPO (nothing by mouth) after midnight (approximately 8 hours before the examination). Any material in the stomach can simulate the appearance of disease.
1015
1016126 . When reviewing patient blood chemistry levels, what is considered the normal creatinine range? 
1017(A) 0.6 to 1.5 mg/ 100 mL 
1018(B) 4.5 to 6 mg/ 100 mL 
1019(C) 8 to 25 mg/ 100 mL 
1020(D) Up to 50 mg/ 100 mL
1021 ------------------------------------------------ (A) Creatinine is a normal alkaline constituent of urine and blood, but increased quantities of creatinine are present in advanced stages of renal disease. Creatinine and BUN blood chemistry levels should be checked prior to beginning an IVU. Increased levels may forecast an increased possibility of contrast media- induced renal effects and poor visualization of the renal collecting systems. The normal creatinine range is 0.6 to 1.5 mg/ 100 mL. The normal BUN range is 8 to 25 mg/ 100 mL.
1022
1023127 . Which of the following medical equipment is used to determine blood pressure? 
10241. Pulse oximeter 
10252. Stethoscope 
10263. Sphygmomanometer 
1027(A) 1 and 2 only 
1028(B) 1 and 3 only 
1029(C) 2 and 3 only 
1030(D) 1, 2, and 3
1031 ------------------------------------------------ (C) A stethoscope and a sphygmomanometer are used together to measure blood pressure. The first sound heard is the systolic pressure, and the normal range is 110 to 140 mm Hg. When the sound is no longer heard , the diastolic pressure is recorded. The normal diastolic range is 60 to 90 mm Hg. Elevated blood pressure is called hypertension. Hypotension, or low blood pressure, is not of concern unless it is caused by injury or disease; in that case, it can result in shock. A pulse oximeter is used to measure a patient's pulse rate and oxygen saturation level.
1032
1033128 . Diseases whose mode of transmission is through the air include 
10341. TB 
10352. mumps 
10363. rubella 
1037(A) 1 only 
1038(B) 1 and 2 only 
1039(C) 1 and 3 only 
1040(D) 1, 2, and 3
1041 ------------------------------------------------ (D) Diseases that are transmitted through the air include TB, rubella (" German measles"), mumps, and influenza. Airborne precautions require the patient to wear a mask to avoid the spread of acid-fast bacilli (in the bronchial secretions of TB patients) or other pathogens during coughing. If the patient is unable or unwilling to wear a mask, the radiographer must wear one. The radiographer should wear gloves, but a gown is required only if flagrant contamination is likely. Patients infected with diseases calling for airborne precautions require a private, specially ventilated (negative-pressure) room. A private room is also indicated for all patients on droplet precautions, that is, with diseases that are transmitted via large droplets expelled from the patient while speaking, sneezing, or coughing. The pathogenic droplets can infect others when they come in contact with the mouth or nasal mucosa or conjunctiva. Rubella (" German measles"), mumps, and influenza are among the diseases spread by droplet contact; a private room is required for the patient, and health care practitioners must use gowns and gloves.
1042
1043129 . A small container holding several doses of medication is termed 
1044(A) an ampoule 
1045(B) a vial 
1046(C) a bolus 
1047(D) a carafe
1048 ------------------------------------------------ (B) Injectable medications are available in two different kinds of containers. An ampoule is a small container that usually holds a single dose of medication. A vial is a somewhat larger container that holds a number of doses of medication . The term bolus is used to describe an amount of fluid to be injected. A carafe is a narrow-mouthed container; it is not likely to be used for medical purposes.
1049
1050130 . Tracheostomy is indicated in cases of tracheal obstruction when the obstruction is located 
1051(A) below the level of the larynx 
1052(B) above the level of the larynx 
1053(C) inferior to the carina 
1054(D) in the right primary bronchus
1055 ------------------------------------------------ (B) Tracheostomy is the surgical opening of the trachea to provide and secure an open airway. A tracheostomy is often performed in emergency situations when there is upper airway obstruction, that is, above the level of the larynx. Conditions requiring a tracheostomy include crushing injury of the tracheal rings, inflamed and swollen tracheal mucous membranes, and aspiration of foreign body.
1056
10571. What is used to account for the differences in tissue sensitivity to ionizing radiation when determining effective dose E?
10581. Tissue weighting factors (Wt)
10592. Radiation weighting factors (Wr)
10603. Absorbed dose
1061(A) 1 only
1062(B) 1 and 2 only
1063(C) 2 and 3 only
1064(D) 1, 2, and 3
1065------------------------------ - (A) The tissue weighting factor (Wt) represents the relative tissue radiosensitivity of irradiated material (e.g., muscle vs. intestinal epithelium vs. bone). The radiation weighting factor (Wr) is a number assigned to different types of ionizing radiations in order to better determine their effect on tissue (e.g., x-ray vs. alpha particles). The Wr of different ionizing radiations depends on the LET of that particular radiation.
10662. According to the National Council on Radiation Protection and Measurements (NCRP), the monthly gestational dose-equivalent limit for embryo/fetus of a pregnant radiographer is
1067(A) 0.1 mSv
1068(B) 0.5 mSv
1069(C) 1.0 mSv
1070(D) 5.0 mSv
1071------------------------------ - (B) The pregnant radiographer poses a special radiation protection consideration, for the safety of the unborn individual. It must be remembered that the developing fetus is particularly sensitive to radiation exposure. Therefore, established guidelines state that the occupational gestational dose-equivalent limit for embryo/fetus of a pregnant radiographer is 5 mSv (500 mrem), not to exceed 0.5 mSv in 1 month. According to the NCRP, the annual occupational whole-body dose-equivalent limit is 50 mSv (5 rem or 5,000 mrem). The annual occupational whole-body dose-equivalent limit for students under the age of 18 years is 1 mSv (100 mrem or 0.1 rem). The annual occupational dose-equivalent limit for the lens of eye is 150 mSv (15 rem). The annual occupational dose-equivalent limit for the thyroid, skin, and extremities is 500 mSv (50 rem).
10723. A time of 1.5 minutes is required for a particular fluoroscopic examination, whose exposure rate is 275 mR/h. What is the approximate radiation exposure for the radiologic staff present in the fluoroscopy room during the examination?
1073(A) 183 mR
1074(B) 68.7 mR
1075(C) 18.33 mR
1076(D) 6.87 mR
1077------------------------------ - (D) If the exposure rate for the examination is 250 mR/h (60 minutes), then a 3-minute examination would be proportionally less
10784. If the exposure rate to an individual standing 4.0 m from a source of radiation is 10 mR/h, what will be the dose received after 20 minutes at a distance of 6 m from the source?
1079(A) 22.5 mR
1080(B) 7.5 mR
1081(C) 4.44 mR
1082(D) 1.48 mR
1083------------------------------ - (D) The relationship between x-ray intensity and distance from the source is expressed in the inverse-square law of radiation.
10845. All the following statements regarding mobile radiographic equipment are true except
1085(A) the exposure cord must permit the operator to stand at least 6 ft from the patient, x-ray tube, and useful beam
1086(B) exposure switches must be the two-stage type
1087(C) a lead apron should be carried with the unit and worn by the radiographer during exposure
1088(D) the radiographer must alert individuals in the area before making the exposure
1089------------------------------ - (B) NCRP Report No. 102 states that the exposure switch on mobile radiographic units shall be so arranged that the operator can stand at least 2 m (6 ft) from the patient, the x-ray tube, and the useful beam. An appropriately long exposure cord accomplishes this requirement. The fluoroscopic and/or radiographic exposure switch or switches must be of the "dead man" type; that is, the exposure will terminate should the switch be released. A lead apron should be carried with every mobile x-ray unit for the operator to wear during the exposure. Lastly, the radiographer must be certain to alert individuals in the area, enabling unnecessary occupants to move away, before making the exposure.
10906. Which of the following cell types has the greatest radiosensitivity in the adult human?
1091(A) Nerve cells
1092(B) Muscle cells
1093(C) Spermatids
1094(D) Lymphocytes
1095------------------------------ - (D) Lymphocytes, a type of white blood cell concerned with the immune system, have the greatest radiosensitivity of all body cells. Spermatids are also highly radiosensitive, although not to the same degree as lymphocytes. Muscle cells have a fairly low radiosensitivity, and nerve cells are the least radiosensitive in the body (in fetal life, however, nerve cells are highly radiosensitive).
10967. Guidelines for the use of protective shielding state that gonadal shielding should be used
10971. if the patient has reasonable reproductive potential
10982. when the gonads are within 5 cm of the collimated field
10993. when tight collimation is not possible
1100(A) 1 only
1101(B) 1 and 2 only
1102(C) 1 and 3 only
1103(D) 2 and 3 only
1104------------------------------ - (B) It is our professional responsibility to minimize exposure dose to both patients and ourselves, and one of the most important ways is with a closely collimated radiation field. Gonadal shielding should be used when the patient is of reproductive age or younger, when the gonads are in or near the collimated field, and when the clinical objectives will not be compromised
11058. The interaction between ionizing radiation and the target molecule that is most likely to occur is the
1106(A) direct effect
1107(B) indirect effect
1108(C) target effect
1109(D) random effect
1110------------------------------ - (B) The principal interactions that occur between x-ray photons and body tissues in the diagnostic x-ray range, the photoelectric effect and Compton scatter, are ionization processes producing photoelectrons and recoil electrons that traverse tissue and subsequently ionize molecules. These interactions occur randomly but can lead to molecular damage in the form of impaired function or cell death. The target theory specifies that DNA molecules are the targets of greatest importance and sensitivity; that is, DNA is the key sensitive molecule. However, since the body has 65 to 80% water, most interactions between ionizing radiation and body cells will involve radiolysis of water rather than direct interaction with DNA. The two major types of effects that occur are the direct effect and the indirect effect. The direct effect usually occurs with high-LET radiations and when ionization occurs at the DNA molecule itself. The indirect effect, which occurs most frequently, happens when ionization takes place away from the DNA molecule in cellular water. However, the energy from the interaction can be transferred to the molecule via a free radical (formed by radiolysis of cellular water). Possible damage to the DNA molecule is diverse. A single main-chain/side-rail scission (break) on the DNA molecule is repairable. A double main-chain/side-rail scission may repair with difficulty or may result in cell death. A double main-chain/side-rail scission on the same "rung" of the DNA ladder results in irreparable damage or cell death. Faulty repair of main-chain breakage can result in cross-linking. Damage to the nitrogenous bases, that is, damage to the base itself or to the rungs connecting the main chains, can result in alteration of base sequences, causing a molecular lesion/point mutation. Any subsequent divisions result in daughter cells with incorrect genetic information.
11119. What is the approximate entrance skin exposure (ESE) for the average anteroposterior (AP) supine abdomen radiograph?
1112(A) 300 rad
1113(B) 300 mrad
1114(C) 35 rad
1115(D) 35 mrad
1116------------------------------ - (B) Patients occasionally will question the radiographer regarding the amount of radiation they are receiving during their examination. Most of these patients are merely curious because they have heard a recent news report about x-rays or have perhaps studied about x-rays in school recently. It is a good idea for radiographers to have some knowledge of average exposure doses for patients who desire this information. The curious patient also can be referred to the medical physicist for more detailed information. The average anteroposterior (AP) supine lumbar spine radiograph delivers an ESE of about 350 mrad (0.35 rad). The average AP supine abdomen radiograph delivers about 300 mrad; the average AP cervical spine radiograph delivers about 80 mrad.
111710. All of the following device(s) are generally used to help reduce patient dose, except
11181. grid
11192. collimator
11203. gonad shield
1121(A) 1 only
1122(B) 1 and 2 only
1123(C) 2 and 3 only
1124(D) 1, 2, and 3
1125------------------------------ - (A) Collimators or other kinds of beam restrictors limit the amount of tissue being irradiated and, therefore, can reduce patient dose significantly. The use of gonadal shielding protects the reproductive organs from unnecessary radiation exposure and should be employed whenever possible. Grids function to absorb scattered radiation before it reaches the image to cause fog. Grids improve the radiographic image considerably; however, their use requires a significant increase in milliampere-seconds, that is, patient dose.
112611. How will x-ray photon intensity be affected if the source-to-image distance (SID) is doubled?
1127(A) Its intensity increases two times.
1128(B) Its intensity increases four times.
1129(C) Its intensity decreases two times.
1130(D) Its intensity decreases four times.
1131------------------------------ - (D) Source-to-image-receptor distance (SID) has a significant impact on x-ray beam intensity (other terms we could use are exposure rate and dose). As the distance between the x-ray tube and IR increases, exposure rate/intensity/dose (and, therefore, radiographic density) decreases according to the inverse-square law. According to the inverse-square law, the exposure rate is inversely proportional to the square of the distance; that is, if the SID is doubled, the resulting beam intensity will be one-fourth the original intensity; if the SID is cut in half, the resulting beam intensity will be 4 times the original intensity.
113212. What is the established annual occupational dose-equivalent limit for the lens of the eye?
1133(A) 10 mSv
1134(B) 50 mSv
1135(C) 150 mSv
1136(D) 250 mSv
1137------------------------------ - (C) According to the NCRP, the annual occupational whole-body dose-equivalent limit is 50 mSv (5 rem or 5,000 mrem). The annual occupational whole-body dose-equivalent limit for students under the age of 18 years is 1 mSv (100 mrem or 0.1 rem). The annual occupational dose-equivalent limit for the lens of eye is 150 mSv (15 rem). The annual occupational dose-equivalent limit for the thyroid, skin, and extremities is 500 mSv (50 rem).
113813. Occupational radiation monitoring is required when it is possible that the individual might receive more than
1139(A) 5 mrem
1140(B) 10 mrem
1141(C) one-tenth the annual dose limit
1142(D) one-fourth the annual dose limit
1143------------------------------ - (C) Different types of monitoring devices are available for the occupationally exposed, and anyone who might receive more than one-tenth the annual dose limit must be monitored. Ionization is the fundamental principle of operation of both the film badge and the pocket dosimeter. In the film badge, the film's silver halide emulsion is ionized by x-ray photons. The pocket dosimeter contains an ionization chamber (containing air), and the number of ions formed (of either sign) is equated to exposure dose. TLDs are radiation monitors that use lithium fluoride crystals. Once exposed to ionizing radiation and then heated, these crystals give off light in proportion to the amount of radiation received. OSL dosimeters are radiation monitors that use aluminum oxide crystals. These crystals, once exposed to ionizing radiation and then subjected to a laser, give off luminescence proportional to the amount of radiation received.
114414. Sources of natural background radiation contributing to whole-body radiation dose include
11451. dental x-rays
11462. terrestrial radionuclides
11473. internal radionuclides
1148(A) 1 only
1149(B) 1 and 2 only
1150(C) 2 and 3 only
1151(D) 1, 2, and 3
1152------------------------------ - (C) The entire population of the world is exposed to varying amounts of background (environmental) radiation. Sources of background radiation are either natural or human-made. Exposure to natural background radiation is a result of cosmic radiation from space (external terrestrial) and naturally radioactive elements within the earth's crust (internal terrestrial) and our own bodies (internal sources, from ingested materials). Naturally, the closer we are to the cosmic radiations from space, the greater our personal exposure will be; living at higher elevations and air travel expose us to greater amounts of radiation. Living or working in a building made of materials derived from the ground exposes us to some background radiation from the naturally radioactive elements found in the earth's crust. The food we eat, the water we drink, and the air we breathe all contribute to the quantity of radiation we ingest and inhale. Human-made radiation, however, is the type of background radiation over which we have some control. Medical and dental x-rays, nuclear power plant environs, and nuclear medicine contribute to our exposure to human-made background radiation.
115315. Irradiation of water molecules within the body and their resulting breakdown is termed
1154(A) epilation
1155(B) radiolysis
1156(C) proliferation
1157(D) repopulation
1158------------------------------ - (B) Radiolysis has to do with the irradiation of water molecules and the formation of free radicals. Free radicals contain enough energy to damage other molecules some distance away. They can migrate to and damage a DNA molecule (indirect hit theory).
115916. Which of the following contributes most to occupational exposure?
1160(A) The photoelectric effect
1161(B) Compton scatter
1162(C) Classic scatter
1163(D) Thompson scatter
1164------------------------------ - (B) In the photoelectric effect, a relatively low-energy photon uses all its energy to eject an inner-shell electron, leaving a vacancy. An electron from the shell above drops down to fill the vacancy and in so doing gives up a characteristic ray. This type of interaction is most harmful to the patient because all the photon energy is transferred to tissue. In Compton scatter, a high-energy incident photon uses some of its energy to eject an outer-shell electron. In so doing, the incident photon is deflected with reduced energy, but it usually retains most of its energy and exits the body as an energetic scattered ray. This scattered ray will either contribute to image fog or pose a radiation hazard to personnel depending on its direction of exit; thus, Compton scatter contributes the most to occupational exposure. In classic scatter, a low-energy photon interacts with an atom but causes no ionization; the incident photon disappears into the atom and then is released immediately as a photon of identical energy but with changed direction. Thompson scatter is another name for classic scatter.
116517. Which of the following is (are) used to account for the differences in tissue characteristics when determining effective dose to biologic material?
11661. Tissue weighting factors (Wt)
11672. Radiation weighting factors (Wr)
11683. Absorbed dose
1169(A) 1 only
1170(B) 1 and 2 only
1171(C) 2 and 3 only
1172(D) 1, 2, and 3
1173------------------------------ - (A) The tissue weighting factor (Wt) represents the relative tissue radiosensitivity of irradiated material (e.g., muscle vs. intestinal epithelium vs. bone). The radiation weighting factor (Wr) is a number assigned to different types of ionizing radiations in order to better determine their effect on tissue (e.g., x-ray vs. alpha particles). The Wr of different ionizing radiations depends on the LET of that particular radiation.
117418. The x-ray interaction with matter that is responsible for the majority of scattered radiation reaching the image receptor (IR) is
1175(A) the photoelectric effect
1176(B) Compton scatter
1177(C) classical scatter
1178(D) Thompson scatter
1179------------------------------ - (B) In the photoelectric effect, a relatively low-energy photon uses all its energy to eject an inner-shell electron, leaving a vacancy. An electron from the shell above drops down to fill the vacancy and in so doing gives up a characteristic ray. This type of interaction is most harmful to the patient because all the photon energy is transferred to tissue. In Compton scatter, a high-energy incident photon ejects an outer-shell electron. In doing so, the incident photon is deflected with reduced energy, but it usually retains most of its energy and exits the body as an energetic scattered ray. This scattered ray will either contribute to image fog or pose a radiation hazard to personnel depending on its direction of exit. In classic scatter, a low-energy photon interacts with an atom but causes no ionization; the incident photon disappears into the atom and then is released immediately as a photon of identical energy but with changed direction. Thompson scatter is another name for classic scatter.
118019. The exposure rate to a body 4 ft from a source of radiation is 16 R/h. What distance from the source would be necessary to decrease the exposure to 6 R/h?
1181(A) 5 ft
1182(B) 7 ft
1183(C) 10 ft
1184(D) 14 ft
1185------------------------------ - (B) The relationship between x-ray intensity and distance from the source is expressed by the inverse-square law of radiation.
118620. With milliamperes (mA) increased to maintain output intensity, how is the ESE affected as the source-to-skin distance (SSD) is increased?
1187(A) The ESE increases.
1188(B) The ESE decreases.
1189(C) The ESE remains unchanged.
1190(D) ESE is unrelated to SSD.
1191------------------------------ - (B) As an x-ray source moves away from an absorber, the x-ray intensity (quantity) decreases. Conversely, as the source of x-rays moves closer to the absorber, the intensity increases. In fluoroscopy, the source of x-rays is 12 to 15 inches below the x-ray tabletop. Since the source-to-object distance (SOD) is so short, patient skin dose can be quite high. Simply increasing the SID will decrease ESE, but mA will have to be increased to maintain the required exit exposure. Although mA is increased to maintain required exit exposure, because of the characteristic divergence of the x-ray beam, ESE will still be less at longer SIDs.
1192Distance has a profound effect on dose received and, therefore, is one of the cardinal rules of radiation protection. As distance from the source increases, dose received decreases.
119321. Late radiation-induced somatic effects include
11941. thyroid cancers
11952. cataractogenesis
11963. genetic mutations
1197(A) 1 only
1198(B) 1 and 2 only
1199(C) 2 and 3 only
1200(D) 1, 2, and 3
1201------------------------------ - (D) Late somatic effects are those that can occur years after initial exposure and are caused by low, chronic exposures. Occupationally exposed personnel are concerned with the late effects of radiation exposure. Bone malignancies, thyroid cancers, leukemia, and skin cancers are examples of carcinogenic somatic effects of radiation. Another example of somatic effects of radiation is cataract formation to the lenses of eyes of individuals accidentally exposed to sufficient quantities of radiation. The lives of many of the early radiation workers were several years shorter than the lives of the general population. Statistics revealed that radiologists, for example, had a shorter life span than physicians of other specialties. Life-span shortening, then, was another somatic effect of radiation. Certainly, these effects should never be experienced today. The human reproductive organs are particularly radiosensitive. Fertility and heredity can be greatly affected by the germ cells produced within the testes (spermatogonia) and ovaries (oogonia). Excessive radiation exposure to the gonads can cause temporary or permanent sterility and/or genetic mutations.
120222. Each time an x-ray beam scatters, its intensity at 1 m from the scattering object is what fraction of its original intensity?
1203(A) 1/10
1204(B) 1/100
1205(C) 1/500
1206(D) 1/1,000
1207------------------------------ - (D) One of the radiation protection guidelines for the occupationally exposed is that the x-ray beam should scatter twice before reaching the operator. Each time the x-ray beam scatters, its intensity at 1 m from the scattering object is one-thousandth of its original intensity. Of course, the operator should be behind a shielded booth while making the exposure, but multiple scatterings further reduce the danger of exposure from scattered radiation.
120823. According to the NCRP, the annual occupational whole-body dose-equivalent limit is
1209(A) 1 mSv
1210(B) 50 mSv
1211(C) 150 mSv
1212(D) 500 mSv
1213------------------------------ - (B) According to the NCRP, the annual occupational whole-body dose-equivalent limit is 50 mSv (5 rem or 5,000 mrem). The annual occupational whole-body dose-equivalent limit for students under the age of 18 years is 1 mSv (100 mrem or 0.1 rem). The annual occupational dose-equivalent limit for the lens of eye is 150 mSv (15 rem). The annual occupational dose-equivalent limit for the thyroid, skin, and extremities is 500 mSv (50 rem). The total gestational dose-equivalent limit for embryo/fetus of a pregnant radiographer is 5 mSv (500 mrem), not to exceed 0.5 mSv in 1 month.
121424. A thermoluminescent dosimetry system would use which of the following crystals?
1215(A) Silver halide
1216(B) Sodium thiosulfate
1217(C) Lithium fluoride
1218(D) Aluminum oxide
1219------------------------------ - (C) TLDs are personnel radiation monitors that use lithium fluoride crystals. Once exposed to ionizing radiation and then heated, these crystals give off light proportional to the amount of radiation received. TLDs are very accurate personal monitors. Even more accurate are optically stimulated luminescence (OSL) dosimeters. OSL dosimeters use aluminum oxide as their sensitive crystal. Silver halide is in film emulsion and sodium thiosul-fate is in fixer solution.
122025. Sources of secondary radiation include
12211. background radiation
12222. leakage radiation
12233. scattered radiation
1224(A) 1 only
1225(B) 1 and 2 only
1226(C) 2 and 3 only
1227(D) 1, 2, and 3
1228------------------------------ - (C) Secondary radiation consists of leakage and scattered radiation. Leakage radiation can be emitted when a defect exists in the tube housing. A significant quantity of scattered radiation is generated within, and emitted from, the patient. Background radiation is naturally occurring radiation that is emitted from the earth and that also exists within our bodies.
122926. All the following have an effect on patient dose except
1230(A) kilovoltage
1231(B) milliampere-seconds
1232(C) focal spot size
1233(D) inherent filtration
1234------------------------------ - (C) The selected milliampere-seconds is directly related to patient dose. That is, if milliampere-seconds are doubled, patient dose is doubled. Similarly, if milliampere-seconds are cut in half, patient dose is cut in half. The selected kilovolts peak is inversely related to patient dose. That is, if the kilovolts peak is increased, patient dose can be decreased because more x-ray photons are transmitted through the patient rather than being absorbed. Inherent filtration is provided by materials that are a permanent part of the tube housing, that is, the glass envelope of the x-ray tube and the oil coolant. Added filtration, usually thin sheets of aluminum, is present to make a total of 2.5 mm Al equivalent for equipment operated above 70 kVp. Filtration is used to decrease patient dose by removing the weak x-rays that have no value but contribute to the skin dose. The effect of focal spot size is principally on radiographic sharpness; it has no effect on patient dose.
123527. The photoelectric effect is more likely to occur with
12361. absorbers having a high Z number
12372. high-energy incident photons
12383. positive contrast media
1239(A) 1 and 2 only
1240(B) 1 and 3 only
1241(C) 2 and 3 only
1242(D) 1, 2, and 3
1243------------------------------ - (B) The photoelectric effect is the interaction between x-ray photons and matter that is largely responsible for patient dose. The photoelectric effect occurs when a relatively low-energy photon uses all its energy to eject an inner-shell electron. That electron is ejected from the atom, leaving a hole in, for example, the K shell. An L-shell electron then drops down to fill the K vacancy and in so doing emits a characteristic ray whose energy equals the difference in binding energies for the K and L shells. The photoelectric effect occurs with high-atomic-number (Z) absorbers such as bone and with positive contrast media.
124428. All the following radiation-exposure responses exhibit a nonlinear threshold dose-response relationship except
1245(A) skin erythema
1246(B) hematologic depression
1247(C) radiation lethality
1248(D) leukemia
1249------------------------------ - (D) The genetic effects of radiation and some somatic effects, such as leukemia, are plotted on a linear dose-response curve. The linear dose-response curve has no threshold; that is, there is no dose below which radiation is absolutely safe. The nonlinear/sigmoidal dose-response curve has a threshold and is thought to be generally correct for most somatic effects—such as skin erythema, epilation, hematologic depression, and radiation lethality (death).
125029. In radiation protection, the product of absorbed dose and the correct modifying factor (rad × QF) is used to determine
1251(A) roentgen (C/kg)
1252(B) rem (Sv)
1253(C) curie (Cu)
1254(D) radiation quality
1255------------------------------ - (B) Rem (dose-equivalent) is the only unit of measurement that expresses the dose-effect relationship. The product of rad (absorbed dose) and the quality factor appropriate for the radiation type is expressed as rem or dose equivalent (DE) and may be used to predict the type and extent of response to radiation.
125630. Which of the following is recommended for the pregnant radiographer?
1257(A) Change dosimeters weekly.
1258(B) Wear a second dosimeter under the lead apron.
1259(C) Wear two dosimeters and switch their positions appropriately.
1260(D) The pregnant radiographer must leave radiation areas for duration of the pregnancy.
1261------------------------------ - (B) Special arrangements are required for occupational monitoring of the pregnant radiographer. The pregnant radiographer will wear two dosimeters—one in its usual place at the collar and the other, a baby/fetal dosimeter, worn over the abdomen and under the lead apron during fluoroscopy. The baby/fetal dosimeter must be identified as such and always must be worn in the same place. Care must be taken not to mix the positions of the two dosimeters. The dosimeters are read monthly, as usual. The pregnant radiographer may not be made to leave the radiation area/department because of her pregnancy.
126231. The annual dose limit for medical imaging personnel includes radiation from
12631. occupational exposure
12642. background radiation
12653. medical x-rays
1266(A) 1 only
1267(B) 1 and 2 only
1268(C) 2 and 3 only
1269(D) 1, 2, and 3
1270------------------------------ - (A) Occupationally exposed individuals are required to use devices that will record and provide documentation of the radiation they receive over a given period of time, traditionally 1 month. The most commonly used personal dosimeters are the OSL, the TLD, and the film badge. These devices must be worn only for documentation of occupational exposure. They must not be worn for any medical or dental x-rays one receives as a patient, and they are not used to measure naturally occurring background radiation.
127132. Which of the following anomalies is (are) possible if an exposure dose of 40 rad (400 mGy) were delivered to a pregnant uterus in the third week of pregnancy?
12721. Skeletal anomaly
12732. Organ anomaly
12743. Neurologic anomaly
1275(A) 1 only
1276(B) 2 only
1277(C) 2 and 3 only
1278(D) 1, 2, and 3
1279------------------------------ - (B) Irradiation during pregnancy, especially in early pregnancy, must be avoided. The fetus is particularly radiosensitive during the first trimester, during much of which time pregnancy may not even be suspected. High-risk examinations include pelvis, hip, femur, lumbar spine, cystograms and urograms, and upper and lower gastrointestinal (GI) series. During the first trimester, specifically the 2nd to 10th weeks of pregnancy (i.e., during major organogenesis), if the radiation dose is sufficient, fetal anomalies can be produced. Skeletal and/or organ anomalies can appear if irradiation occurs in the early part of this time period, and neurologic anomalies can be formed in the latter part; mental retardation and childhood malignant diseases, such as cancers or leukemia, and retarded growth/development also can result from irradiation during the first trimester. Fetal irradiation during the second and third trimesters is not likely to produce anomalies but rather, with sufficient dose, some type of childhood malignant disease. Fetal irradiation during the first 2 weeks of gestation can result in embryonic resorption or spontaneous abortion. It must be emphasized, however, that the likelihood of producing fetal anomalies at doses below 20 rad is exceedingly small and that most general diagnostic examinations are likely to deliver fetal doses of less than 1 to 2 rad.
128033. The effects of radiation on biologic material depend on several factors. If a quantity of radiation is delivered to a body over a long period of time, the effect
1281(A) will be greater than if it were delivered all at one time
1282(B) will be less than if it were delivered all at one time
1283(C) has no relation to how it is delivered in time
1284(D) depends solely on the radiation quality
1285------------------------------ - (B) The effects of a quantity of radiation delivered to a body depend on the amount of radiation received, the size of the irradiated area, and how the radiation is delivered in time. If the radiation is delivered in portions over a period of time, it is said to be fractionated and has a less harmful effect than if it were delivered all at once because cells have an opportunity to repair, and some recovery occurs between doses.
128634. Medical and dental radiation accounts for what percentage of the general public's exposure to human-made radiation?
1287(A) 10%
1288(B) 50%
1289(C) 75%
1290(D) 90%
1291------------------------------ - (D) Artificial/human-made sources of radiation include radioactive fallout, industrial radiation, and medical and dental x-rays. About 90% of the general public's exposure to artificial radiation is from medical and dental x-rays. It is our professional obligation, therefore, to keep our patient's radiation dose to a minimum.
129235. Which of the following is (are) composed of nondividing, differentiated cells?
12931. Neurons and neuroglia
12942. Epithelial tissue
12953. Lymphocytes
1296(A) 1 only
1297(B) 1 and 2 only
1298(C) 1 and 3 only
1299(D) 1, 2, and 3
1300------------------------------ - (A) Nondividing, differentiated cells are specialized, mature cells that do not undergo mitosis. Having these qualities, they are rendered radioresistant, according to the theory proposed by Bergonié and Tribondeau. The adult nervous system is composed of nondividing, differentiated cells and thus is the most radioresistant system in the adult. Epithelial tissue and lymphocytes contain many precursor stem cells and hence are among the most radiosensitive cells in the body.
130136. How does filtration affect the primary beam?
1302(A) It increases the average energy of the primary beam.
1303(B) It decreases the average energy of the primary beam.
1304(C) It makes the primary beam more penetrating.
1305(D) It increases the intensity of the primary beam.
1306------------------------------ - (A) X-rays produced at the tungsten target make up a heterogeneous primary beam. Filtration serves to eliminate the softer, less penetrating photons, leaving an x-ray beam of higher average energy. Filtration is important in patient protection because unfiltered, low-energy photons that are not energetic enough to reach the IR stay in the body and contribute to total patient dose.
130737. What is the minimum lead requirement for lead aprons, according to the NCRP?
1308(A) 0.05 mm Pb
1309(B) 0.50 mm Pb
1310(C) 0.25 mm Pb
1311(D) 1.0 mm Pb
1312------------------------------ - (B) Lead aprons are secondary radiation barriers and must contain at least 0.25 mm Pb equivalent (according to CFR 20), usually in the form of lead-impregnated vinyl. Many radiology departments routinely use lead aprons containing 0.5 mm Pb (the NCRP recommends 0.5 mm Pb equivalent minimum). These aprons are heavier, but they attenuate a higher percentage of scattered radiation.
131338. An optically stimulated luminescence dosimeter contains which of the following detectors?
1314(A) Gadolinium
1315(B) Aluminum oxide
1316(C) Lithium fluoride
1317(D) Photographic film
1318------------------------------ - (B) Different types of monitoring devices are available for the occupationally exposed. The film badge has photographic film; the pocket dosimeter contains an ionization chamber; TLDs use lithium fluoride crystals. OSL dosimeters are personnel radiation monitors that use aluminum oxide crystals. These crystals, once exposed to ionizing radiation and then subjected to a laser, give off luminescence proportional to the amount of radiation received.
131939. Immature cells are referred to as
13201. undifferentiated cells
13212. stem cells
13223. genetic cells
1323(A) 1 only
1324(B) 1 and 2 only
1325(C) 1 and 3 only
1326(D) 1, 2, and 3
1327------------------------------ - (B) Cells are frequently identified by their stage of development. Immature cells may be referred to as undifferentiated or stem cells. Immature cells are much more radiosensitive than mature cells.
132840. What is the term used to describe x-ray photon interaction with matter and the transference of part of the photon's energy to matter?
1329(A) Absorption
1330(B) Scattering
1331(C) Attenuation
1332(D) Divergence
1333------------------------------ - (B) Scattering occurs when there is partial transfer of the proton's energy to matter, as in the Compton effect. Absorption occurs when an x-ray photon interacts with matter and disappears, as in the photoelectric effect. The reduction in the intensity (quantity) of an x-ray beam as it passes through matter is termed attenuation. Divergence refers to a directional characteristic of the x-ray beam as it is emitted from the focal spot.
133441. What is the approximate ESE for the average upright PA chest radiograph using 115 kVp and a grid?
1335(A) 20 rad
1336(B) 20 mrad
1337(C) 200 rad
1338(D) 200 mrad
1339------------------------------ - (B) Patients occasionally will question the radiographer about the amount of radiation they are receiving during their examination. Most of these patients are merely curious because they have heard a recent news report about x-rays or have perhaps studied about x-rays in school recently. It is a good idea for radiographers to have some knowledge of average exposure doses for patients who desire this information. The curious patient can also be referred to the medical physicist for more detailed information. The average high-kilovolt-age chest radiograph with grid delivers an ESE of about 20 mrad (0.020 rad). The same chest radiograph done without a grid at 80 kVp would deliver an ESE of about 12 mrad (0.012 rad). The average AP supine lumbar spine radiograph delivers an ESE of about 350 mrad (0.35 rad). The average AP supine abdomen radiograph delivers about 300 mrad; the average AP cervical spine radiograph delivers about 80 mrad.
134042. To be in compliance with radiation safety standards, the fluoroscopy exposure switch must
1341(A) sound during fluoro-on time
1342(B) be on a 6-ft-long cord
1343(C) terminate fluoro after 5 minutes
1344(D) be the "dead man" type
1345------------------------------ - (D) For radiation safety, the fluoroscopy exposure switch must be of the "dead man" type. When the foot is removed from the fluoro pedal, the "dead man" switch will terminate the exposure immediately. There must also be a fluoroscopy timer that will either sound or interrupt exposure after 5 minutes of fluoroscopy.
134643. Primary radiation barriers must be at least how high?
1347(A) 5 ft
1348(B) 6 ft
1349(C) 7 ft
1350(D) 8 ft
1351------------------------------ - (C) Radiation protection guidelines have established that primary radiation barriers must be 7 ft high. Primary radiation barriers are walls that the primary beam might be directed toward. They usually contain 1.5 mm of lead (1/16 in.), but this may vary depending on use factor, and so on.
135244. The annual dose limit for occupationally exposed individuals is valid for
1353(A) alpha, beta, and x-radiations
1354(B) x- and gamma radiations only
1355(C) beta, x-, and gamma radiations
1356(D) all ionizing radiations
1357------------------------------ - (C) The occupational dose limit is valid for beta, x-, and gamma radiations. Because alpha radiation is so rapidly ionizing, traditional personnel monitors will not record alpha radiation. However, because alpha particles are capable of penetrating only a few centimeters of air, they are practically harmless as an external source.
135846. Patient dose increases as fluoroscopic
1359(A) FOV increases
1360(B) FOV decreases
1361(C) FSS increases
1362(D) FSS decreases
1363------------------------------ - (B) During fluoroscopic procedures, as field of view (FOV) decreases, magnification of the output screen image increases, and contrast and resolution improve. The focal point on an image intensifier's 6-in. field/mode is further away from the output phosphor than the focal point on the normal mode; therefore, the output image is magnified. Because less minification takes place, the image is not as bright. Exposure factors are increased automatically to compensate for the loss in brightness with smaller FOVs. Focal spot size (FSS) is unrelated to patient dose.
136447. Types of gonadal shielding include which of the following?
13651. Flat contact
13662. Shaped contact (contour)
13673. Shadow
1368(A) 1 only
1369(B) 1 and 2 only
1370(C) 2 and 3 only
1371(D) 1, 2, and 3
1372------------------------------ - (D) Gonadal shielding should be used whenever appropriate and possible during radiographic and fluoroscopic examinations. Flat contact shields are useful for simple recumbent (AP, PA) studies, but when the examination necessitates obtaining oblique, lateral, or erect projections, they become less efficient. Shaped contact (contour) shields are best because they enclose the male reproductive organs and remain in position in oblique, lateral, and erect positions. Shadow shields that attach to the tube head are particularly useful for surgical sterile fields.
137348. What unit of measure is used to express ionizing radiation dose to biologic material?
1374(A) Roentgen (C/kg)
1375(B) Rad (Gy)
1376(C) Rem (Sv)
1377(D) RBE
1378------------------------------ - (C) Rad is an acronym for radiation absorbed dose; it measures the energy deposited in any material. Roentgen is the unit of exposure; it measures the quantity of ionizations in air. Rem is an acronym for radiation-equivalent m an; it includes the RBE specific to the tissue irradiated and, therefore, is a valid unit of measurement for the dose to biologic tissue.
137949. LET is best defined as
13801. a method of expressing radiation quality
13812. a measure of the rate at which radiation energy is transferred to soft tissue
13823. absorption of polyenergetic radiation
1383(A) 1 only
1384(B) 1 and 2 only
1385(C) 1 and 3 only
1386(D) 1, 2, and 3
1387------------------------------ - (B) When biologic material is irradiated, there are a number of modifying factors that determine what kind and how much response will occur in the material. One of these factors is LET, which expresses the rate at which particulate or photon energy is transferred to the absorber. Because different kinds of radiation have different degrees of penetration in different materials, it is also a useful way of expressing the quality of the radiation.
138850. For exposure to 1 rad of each of the following ionizing radiations, which would result in the greatest dose to the individual?
1389(A) External source of 1-MeV x-rays
1390(B) External source of diagnostic x-rays
1391(C) Internal source of alpha particles
1392(D) External source of beta particles
1393------------------------------ - (C) Electromagnetic radiations such as x-rays and gamma rays are considered low-LET radiations because they produce fewer ionizations than the highly ionizing particulate radiations such as alpha particles. Alpha particles are large and heavy (two protons and two neutrons), and although they possess a great deal of kinetic energy (approximately 5 MeV), their energy is lost rapidly through multiple ionizations (approximately 40,000 atoms/cm of air). As an external source, alpha particles are almost harmless because they ionize the air very quickly and never reach the individual. As internal sources, however, they ionize tissues and are potentially the most harmful. It may be stated that the alpha particle has one of the highest LETs of all ionizing radiations.
139451. The skin response to radiation exposure that appears as hair loss is known as
1395(A) dry desquamation
1396(B) moist desquamation
1397(C) erythema
1398(D) epilation
1399------------------------------ - (D) The various skin responses to irradiation include all four choices. The first noticeable response would be erythema, a reddening of the skin very much like sunburn. Dry desquamation could follow; it is a dry peeling of the skin. Moist desquamation is peeling with associated pus-like fluid. Epilation is hair loss; it can be temporary or permanent depending on sensitivity and dose.
140052. Biologic material is least sensitive to irradiation under which of the following conditions?
1401(A) Anoxic
1402(B) Hypoxic
1403(C) Oxygenated
1404(D) Deoxygenated
1405------------------------------ - (A) Tissue is most sensitive to radiation when it is oxygenated and least sensitive when it is devoid of oxygen. Anoxic refers to tissue without oxygen; hypoxic refers to tissue with little oxygen. Anoxic and hypoxic tumors typically are avascular (with little or no blood supply) and, therefore, more radioresistant.
140653. The reduction in the intensity of an x-ray beam as it passes through material is termed
1407(A) absorption
1408(B) scattering
1409(C) attenuation
1410(D) divergence
1411------------------------------ - (C) The reduction in the intensity (quantity) of an x-ray beam as it passes through matter as a result of absorption and scatter is called attenuation. Absorption occurs when an x-ray photon interacts with matter and disappears, as in the photoelectric effect. Scattering occurs when there is partial transfer of energy to matter, as in the Compton effect.
141254. Which type of dose-response relationship represents radiation-induced leukemia and genetic effects?
1413(A) Linear, threshold
1414(B) Nonlinear, threshold
1415(C) Linear, nonthreshold
1416(D) Nonlinear, nonthreshold
1417------------------------------ - (C) Radiation-induced malignancy, leukemia, and genetic effects are late effects (or stochastic effects) of radiation exposure. These can occur years after survival of an acute radiation dose or after exposure to low levels of radiation over a long period of time. Radiation workers need to be especially aware of the late effects of radiation because their exposure to radiation is usually low level over a long period of time. Occupational radiation protection guidelines, therefore, are based on late effects of radiation according to a linear, non-threshold dose-response curve.
141855. A dose of 25 rad to the fetus during the seventh or eighth week of pregnancy is likely to cause which of the following?
1419(A) Spontaneous abortion
1420(B) Skeletal anomalies
1421(C) Neurologic anomalies
1422(D) Organogenesis
1423------------------------------ - (C) During the first trimester, specifically the second through eighth weeks of pregnancy (during major organogenesis), if the radiation dose is at least 20 rad, fetal anomalies can be produced. Skeletal anomalies usually appear if irradiation occurs in the early part of this time period, and neurologic anomalies are formed in the latter part; mental retardation and childhood malignant diseases, such as cancers or leukemia, also can result from irradiation during the first trimester. Fetal irradiation during the second and third trimesters is not likely to produce anomalies but rather, with sufficient dose, some type of childhood malignant disease. Fetal irradiation during the first 2 weeks of gestation can result in spontaneous abortion. It must be emphasized that the likelihood of producing fetal anomalies at doses below 20 rad is exceedingly small and that most general diagnostic examinations are likely to deliver fetal doses of less than 1 to 2 rad.
142456. Late effects of radiation, whose incidence is dose related and for which there is no threshold dose, are referred to as
1425(A) nonstochastic
1426(B) stochastic
1427(C) chromosomal aberration
1428(D) hematologic depression
1429------------------------------ - (B) Late or long-term effects of radiation can occur in tissues that have survived a previous irradiation months or years earlier. These late effects, such as carcinogenesis and genetic effects, are "all-or-nothing" effects—either the organism develops cancer or it does not. Most late effects do not have a threshold dose; that is, any dose, however small, can induce an effect. Increasing that dose will increase the likelihood of the occurrence but will not affect its severity; these effects are termed stochastic. Nonstochastic effects are those that will not occur below a particular threshold dose and that increase in severity as the dose increases. Early effects of radiation exposure are in response to relatively high radiation doses. These should never occur in diagnostic radiology; they occur only in response to doses much greater than those used in diagnostic radiology. One of the effects that may be noted in such a circumstance is the hematologic effect—reduced numbers of white blood cells, red blood cells, and platelets in the circulating blood. Immediate local tissue effects can include effects on the gonads (temporary infertility) and on the skin (epilation, erythema). Acute radiation lethality, or radiation death, occurs after an acute exposure and results in death in weeks or days.
143057. Which of the following methods can be used to reduce radiation exposure to a recently fertilized ovum?
14311. Elective booking
14322. Patient questionnaire
14333. The 10-day rule
1434(A) 1 only
1435(B) 1 and 2 only
1436(C) 2 and 3 only
1437(D) 1, 2, and 3
1438------------------------------ - (D) In consideration of the potential risk, female patients of childbearing age should be questioned regarding their last menstrual period (LMP) and the possibility of their being pregnant. Facilities offering radiologic services should make inquiries of their female patients regarding LMP and advise them of the risk associated with radiation exposure during pregnancy and the advisability of elective booking. The 10-day rule identifies the first 10 days following the onset of menses as the safest time to schedule elective procedures of the abdomen/pelvis. In addition to supporting the as low as reasonably achievable (ALARA) concept, many institutions also use a patient questionnaire as a guide for scheduling elective abdominal x-ray examinations on women of reproductive age. The patient completes a form that requests information concerning her LMP and the possibility of her being pregnant. In place of either or both of the preceding—or in addition to them—posters can be obtained or signs can be made that caution the patient to tell the radiologic technologist if she suspects that she might be pregnant. Most facilities will post these signs in waiting rooms, dressing rooms, and radiographic rooms.
143958. Classify the following tissues in order of increasing radiosensitivity:
1440 
14411. Liver cells
14422. Intestinal crypt cells
14433. Muscle cells
1444(A) 1, 3, 2
1445(B) 2, 3, 1
1446(C) 2, 1, 3
1447(D) 3, 1, 2
1448------------------------------ - (D) According to Bergonié and Tribondeau, the most radiosensitive cells are undifferentiated, rapidly dividing cells, such as lymphocytes, intestinal crypt (of Lieberkühn) cells, and spermatogonia. Liver cells are among the types of cells that are somewhat differentiated and capable of mitosis. These characteristics render them somewhat radiosensitive. Muscle cells, as well as nerve cells and red blood cells, are highly differentiated and do not divide. Therefore, in order of increasing sensitivity (from least to greatest sensitivity), the cells are muscle, liver, and then intestinal crypt cells.
144959. The largest amount of diagnostic x-ray absorption is most likely to occur in which of the following tissues?
1450(A) Lung
1451(B) Adipose
1452(C) Muscle
1453(D) Bone
1454------------------------------ - (D) Our bodies contain a variety of tissues having a variety of tissue densities. These tissues densities afford differing degrees of resistance to the passage of x-ray photons. Tissues having greater density absorb more of the x-ray beam (recall the photoelectric effect). Soft tissues are fairly easily penetrated to varying degrees; that is, lung and adipose are easier to penetrate than muscle. Bone has much higher tissue mass density and, therefore, absorbs more of the x-ray beam.
145560. According to NCRP regulations, leakage radiation from the x-ray tube must not exceed
1456(A) 10 mR/h
1457(B) 100 mR/h
1458(C) 10 mR/min
1459(D) 100 mR/min
1460------------------------------ - (B) X-ray photons produced in the x-ray tube can radiate in directions other than the one desired. The tube housing, therefore, is constructed so that very little of this leakage radiation is permitted to escape. The regulation states that leakage radiation must not exceed 100 mR/h at 1 m while the tube is operated at maximum potential.
146161. Which of the following most effectively minimizes radiation exposure to the patient?
1462(A) Small focal spot
1463(B) Low-ratio grids
1464(C) Increased SID
1465(D) High-speed intensifying screens
1466------------------------------ - (D) Focal spot size affects recorded detail and x-ray tube heat limits—it has no effect on patient dose. Low-ratio grids, although they require fewer milliampere-seconds than high-ratio grids, are not a means of patient protection. Long SIDs usually require the use of higher milliampere-seconds and so would not be an effective means of patient protection. The use of high-speed intensifying screens enables the use of lower milliampere-second values and, therefore, is an important consideration in limiting patient dose. Limiting the irradiated field size, through collimation or other beam restriction, is perhaps the most effective way of controlling patient exposure dose.
146762. Which of the following statements is (are) true with respect to radiation safety in fluoroscopy?
14681. Tabletop radiation intensity must not exceed 2.1 R/min/mA.
14692. Tabletop radiation intensity must not exceed 10 R/min.
14703. In high-level fluoroscopy, tabletop intensity up to 20 R/min is permitted.
1471(A) 1 only
1472(B) 1 and 2 only
1473(C) 2 and 3 only
1474(D) 1, 2, and 3
1475------------------------------ - (D) In fluoroscopy, the source of x-rays is 12 to 15 in. below the x-ray tabletop. Since the source to object distance (SOD) is so short, patient skin dose can be quite high. Consequently, the x-ray intensity at the tabletop is limited to keep patient dose (ESE) within safe limits. The radiation protection guidelines state that x-ray intensity at tabletop must not exceed 2.1 R/min/mA at 80 kVp. In equipment without high-level fluoroscopy capability, the guideline can be expressed as 10 R/min tabletop limit. In equipment with high-level fluoroscopy capability, the tabletop limit is 20 R/min.
147664. Which of the following account(s) for an x-ray beam's heterogeneity?
14771. Incident electrons interacting with several layers of tungsten target atoms
14782. Energy differences among incident electrons
14793. Electrons moving to fill different shell vacancies
1480(A) 1 only
1481(B) 1 and 2 only
1482(C) 1 and 3 only
1483(D) 1, 2, and 3
1484------------------------------ - (D) The x-ray photons produced at the tungsten target make up a heterogeneous beam, a spectrum of photon energies. This is accounted for by the fact that the incident electrons have differing energies. Also, the incident electrons travel through several layers of tungsten target material, lose energy with each interaction, and, therefore, produce increasingly weaker photons. During characteristic x-ray production, vacancies may be filled in the K, L, or M shells, which differ from each other in binding energies, and, therefore, photons with varying amounts of energy are emitted.
148565. Which of the following factors will affect both the quality and the quantity of the primary beam?
14861. Half-value layer (HVL)
14872. Kilovolts (kV)
14883. Milliamperes (mA)
1489(A) 1 only
1490(B) 1 and 2 only
1491(C) 1 and 3 only
1492(D) 1, 2, and 3
1493------------------------------ - (B) Kilovoltage (kV) and the half-value layer (HVL) effect a change in both the quantity and the quality of the primary beam. The principal qualitative factor of the primary beam is kilovoltage, but an increase in kilovoltage will also increase the number of photons produced at the target. HVL, defined as the amount of material necessary to decrease the intensity of the beam to one-half, therefore changes both beam quality and beam quantity. Milliamperage is directly proportional to x-ray intensity (quantity) but is unrelated to the quality of the beam.
149466. Diagnostic x-radiation may be correctly described as
1495(A) low energy, low LET
1496(B) low energy, high LET
1497(C) high energy, low LET
1498(D) high energy, high LET
1499------------------------------ - (A) X-radiation used for diagnostic purposes is of relatively low energy. Kilovoltages of up to 150 kV are used, as compared with radiations having energies of up to several million volts. Linear energy transfer (LET) refers to the rate at which energy is transferred from ionizing radiation to soft tissue. Particulate radiations, such as alpha particles, have mass and charge and, therefore, lose energy rapidly as they penetrate only a few centimeters of air. X- and gamma radiations, having no mass or charge, are low-LET radiations.
150067. Primary radiation barriers usually require which thickness of shielding?
1501(A) ¼-in. lead
1502(B) -in. lead
1503(C) 1/16-in. lead
1504(D) 1/32-in. lead
1505------------------------------ - (C) Examples of primary barriers are the lead walls and doors of a radiographic room, that is, any surface that could be struck by the useful beam. Primary protective barriers of typical installations generally consist of walls with 1/16 in. (1.5 mm) of lead and 7 ft high. Secondary radiation is defined as leakage and/or scattered radiation. The x-ray tube housing protects from leakage radiation, as stated earlier. The patient is the source of most scattered radiation. Secondary radiation barriers include that portion of the walls above 7 ft in height; this area requires only 1/32 in. of lead. The control booth is also a secondary barrier, toward which the primary beam must never be directed.
150668. Which of the following groups of exposure factors will deliver the least patient dose?
1507(A) 300 mA, 250 ms, 70 kVp
1508(B) 300 mA, 125 ms, 80 kVp
1509(C) 400 mA, 90 ms, 80 kVp
1510(D) 600 mA, 30 ms, 90 kVp
1511------------------------------ - (D) Selection of exposure factors has a significant impact on patient dose. Remember that milliampere-seconds (mAs) are used to regulate the quantity of radiation delivered to the patient and kilovolts peak (kVp) determines the penetrability of the x-ray beam. As kilovoltage is increased, more high-energy photons are produced, and the overall average energy of the beam is increased. An increase in milliampere-seconds increases the number of photons produced at the target, but milliampere-seconds are unrelated to photon energy. Generally speaking, then, in an effort to keep radiation dose to a minimum, it makes sense to use the lowest mAs setting and the highest kVp setting that will produce the desired radiographic results. An added benefit is that at high kilovolts peak and low milliampere-second values, the heat delivered to the x-ray tube is lower, and tube life is extended.
151269. For radiographic examinations of the skull, it is generally preferred that the skull be examined in the
1513(A) AP projection
1514(B) PA projection
1515(C) erect position
1516(D) supine position
1517------------------------------ - (B) Because the primary x-ray beam has a poly-energetic (heterogeneous) nature, the entrance or skin dose is significantly greater than the exit dose. This principle may be employed in radiation protection by placing particularly radiosensitive organs away from the primary beam. To place the gonads further from the primary beam and reduce gonadal dose, abdominal radiography should be performed in the posteroanterior (PA) position whenever possible. Dose to the lens is decreased significantly when skull radiographs are performed in the PA position.
151870. According to the NCRP, the annual occupational dose-equivalent limit (50 rem) to the thyroid, skin, and extremities is
1519(A) 50 mSv
1520(B) 150 mSv
1521(C) 500 mSv
1522(D) 1,500 mSv
1523------------------------------ - (C) According to the NCRP, the annual occupational whole-body dose-equivalent limit is 50 mSv (5 rem or 5,000 mrem). The annual occupational whole-body dose-equivalent limit for students under the age of 18 years is 1 mSv (100 mrem or 0.1 rem). The annual occupational dose-equivalent limit for the lens of eye is 150 mSv (15 rem). The annual occupational dose-equivalent limit for the thyroid, skin, and extremities is 500 mSv (50 rem). The total gestational dose-equivalent limit for embryo/fetus of a pregnant radiographer is 5 mSv (500 mrem), not to exceed 0.5 mSv in 1 month.
152471. The skin response to radiation exposure, which appears as reddening of the irradiated skin area, is known as
1525(A) dry desquamation
1526(B) moist desquamation
1527(C) erythema
1528(D) epilation
1529------------------------------ - (C) The first noticeable skin response to excessive irradiation would be erythema, a reddening of the skin very much like sunburn. Dry desquamation, a dry peeling of the skin, may follow. Moist desquamation is peeling with associated puslike fluid. Epilation, or hair loss, may be temporary or permanent depending on sensitivity and dose.
153073. What is the intensity of scattered radiation perpendicular to and 1 m from a patient compared with the useful beam at the patient's surface?
1531(A) 0.01%
1532(B) 0.1%
1533(C) 1.0%
1534(D) 10.0%
1535------------------------------ - (B) The patient is the most important radiation scatterer during both radiography and fluoroscopy. In general, at 1 m from the patient, the intensity is reduced by a factor of 1,000 to about 0.1% of the original intensity. Successive scatterings can reduce the intensity to unimportant levels.
153675. An increase of 1.0 mm added aluminum filtration of the x-ray beam would have which of the following effects?
15371. Increase in average energy of the beam
15382. Increase in patient skin dose
15393. Increase in milliroentgen output
1540(A) 1 only
1541(B) 1 and 2 only
1542(C) 2 and 3 only
1543(D) 1, 2, and 3
1544------------------------------ - (A) Aluminum filters are used to decrease patient skin dose by absorbing the low-energy photons (therefore, decreased milliroentgen output) that do not contribute to the image but do contribute to patient skin dose. HVL is defined as that thickness of any absorber that will decrease the intensity of a particular beam to one-half its original value. As filtration of an x-ray beam is increased, the overall average energy of the resulting beam is greater (because the low-energy photons have been removed) and, therefore, the HVL thickness required would be greater.
154576. Aluminum filtration has its greatest effect on
1546(A) low-energy x-ray photons
1547(B) high-energy x-ray photons
1548(C) low-energy scattered photons
1549(D) high-energy scattered photons
1550------------------------------ - (A) X-ray photons emerging from the focal spot comprise a heterogeneous primary beam. There are many low-energy x-rays that, if not removed, would contribute significantly to patient skin dose. These low-energy photons are too weak to penetrate the patient and expose the IR; they simply penetrate a small thickness of tissue before being absorbed. Filters, usually made of aluminum, are used in radiography to reduce patient dose by removing this low-energy radiation (i.e., decreased beam intensity) and resulting in an x-ray beam of higher average energy. Total filtration is composed of inherent filtration plus added filtration. X-ray photons scatter only after they have interacted with the absorber/patient; scatter is unrelated to filtration.
155177. The amount of time that x-rays are being produced and directed toward a particular wall is referred to as the
1552(A) workload
1553(B) use factor
1554(C) occupancy factor
1555(D) controlling factor
1556------------------------------ - (B) Use factor describes the percentage of time that the primary beam is directed toward a particular wall. The use factor is one of the factors considered in determining protective barrier thickness. Another is workload, which is determined by the number of x-ray exposures made per week. Occupancy factor is a reflection of who occupies particular areas (radiation workers or nonradiation workers) and is another factor used in determining radiation barrier thickness.
155778. The operation of personnel radiation monitoring devices can depend on which of the following?
15581. Ionization
15592. Luminescence
15603. Thermoluminescence
1561(A) 1 only
1562(B) 1 and 2 only
1563(C) 2 and 3 only
1564(D) 1, 2, and 3
1565------------------------------ - (D) Ionization is the fundamental principle of operation of both the film badge and the pocket dosimeter. In the film badge, the film's silver halide emulsion is ionized by x-ray photons. The pocket dosimeter contains an ionization chamber, and the number of ionizations taking place may be equated to the exposure dose. TLDs contain lithium fluoride crystals that undergo characteristic changes on irradiation. When the crystals are subsequently heated, they emit a quantity of visible (thermo) luminescence/light in proportion to the amount of radiation absorbed. OSL dosimeters contain aluminum oxide crystals that also undergo characteristic changes on irradiation. When the Al2O3 crystals are stimulated by a laser, they emit (optically stimulated) luminescence/light in proportion to the amount of radiation absorbed.
156679. Which of the following result(s) from restriction of the x-ray beam?
15671. Less scattered radiation production
15682. Less patient hazard
15693. Less radiographic contrast
1570(A) 1 only
1571(B) 1 and 2 only
1572(C) 2 and 3 only
1573(D) 1, 2, and 3
1574------------------------------ - (B) As the size of the irradiated field decreases, scattered radiation production and patient hazard decrease. If the amount of scattered radiation decreases, then radiographic contrast is higher (shorter scale).
157580. Which acute radiation syndrome requires the largest exposure before any effects become apparent?
1576(A) Hematopoietic
1577(B) Gastrointestinal
1578(C) Central nervous system (CNS)
1579(D) Skeletal
1580------------------------------ - (C) Radiation effects that appear days or weeks following exposure (early effects) are in response to high radiation doses; this is called acute radiation syndrome. These effects should never occur in diagnostic radiology; they occur only in response to much greater doses. Sufficient exposure of the hematologic system to ionizing radiation can result in nausea, vomiting, diarrhea, decreased blood cells count, and infection. Very large exposure of the GI system (1,000-5,000 rad) causes severe damage to the (stem) cells lining the GI tract. This can result in nausea, vomiting, diarrhea, blood changes, and hemorrhage. Exposure greater than 5,000 rad is required to affect the normally resilient CNS.
158181. Early symptoms of acute radiation syndrome include
15821. leukopenia
15832. nausea and vomiting
15843. cataracts
1585(A) 1 and 2 only
1586(B) 2 only
1587(C) 1 and 3 only
1588(D) 2 and 3 only
1589------------------------------ - (A) Occupationally exposed individuals generally receive small amount of low-energy radiation over a long period of time. These individuals, therefore, are concerned with the potential long-term effects of radiation, such as carcinogenesis (including leukemia) and cataractogenesis. However, if a large amount of radiation is delivered to the whole body at one time, the short-term early somatic effects must be considered. If the whole body receives 600 rad at one time, acute radiation syndrome is likely to occur. Early signs of acute radiation syndrome include nausea, vomiting, diarrhea, fatigue, and leukopenia (decreased white blood cells count); these occur in the first (prodromal) stage of acute radiation syndrome.
159084. Possible responses to irradiation in utero include
15911. spontaneous abortion
15922. congenital anomalies
15933. childhood malignancies
1594(A) 1 only
1595(B) 1 and 2 only
1596(C) 2 and 3 only
1597(D) 1, 2, and 3 only
1598------------------------------ - (D) Irradiation during pregnancy, especially in early pregnancy, is avoided because the fetus is particularly radiosensitive during the first trimester. Especially high-risk examinations include pelvis, hip, femur, lumbar spine, cystograms and urograms, upper GI series, and barium enema (BE) examinations. During the 2nd through 10th weeks of pregnancy (i.e., during major organogenesis), fetal anomalies can be produced. Skeletal and/or organ anomalies can appear if irradiation occurs early on, and neurologic anomalies can be formed in the latter part; mental retardation and childhood malignant diseases can also result from irradiation during the first trimester. Fetal irradiation during the second and third trimesters, with sufficient dose, can cause some type of childhood malignant disease. Fetal irradiation during the first 2 weeks of gestation most likely will result in embryonic resorption or spontaneous abortion. It must be emphasized that the likelihood of producing fetal anomalies at doses below 20 rad is exceedingly small and that most general diagnostic examinations are likely to deliver fetal doses of less than 1 to 2 rad.
159985. The Bucky slot cover is in place to protect the
16001. patient
16012. fluoroscopist
16023. technologist
1603(A) 1 only
1604(B) 1 and 2 only
1605(C) 2 and 3 only
1606(D) 1, 2, and 3
1607------------------------------ - (C) All fluoroscopic equipment has protective devices and protocols to protect the patient and user. Fluoroscopic equipment must provide at least 12 in. (30 cm) and preferably 15 in. (38 cm) between the x-ray source (focal spot) and the x-ray tabletop (patient), according to NCRP Report No. 102. The tabletop intensity of the fluoroscopic beam must not exceed 10 R/min or 2.1 R/min/mA. With under-table fluoroscopic tubes, a Bucky slot closer/cover having at least the equivalent of 0.25 mm Pb must be available to attenuate scattered radiation coming from the patient, posing a radiation hazard to the fluoroscopist and radiographer. Fluoroscopic milliamperes must not exceed 5 mA. Because the image intensifier functions as a primary barrier, it must have a lead equivalent of at least 2.0 mm. A cumulative timing device must be available to signal the fluoroscopist when a maximum of 5 minutes of fluoroscopy time has elapsed. Because occupational exposure to scattered radiation is of considerable importance in fluoroscopy, a protective curtain/drape of at least 0.25 mm Pb equivalent must be placed between the patient and fluoroscopist.
160886. Which type of personnel radiation monitor can provide an immediate reading?
1609(A) Thermoluminescent dosimeter (TLD)
1610(B) Optically stimulated luminescence (OSL)
1611(C) Film badge
1612(D) Ionization chamber
1613------------------------------ - (D) The pocket dosimeter, or pocket ionization chamber, resembles a penlight. Within the dosimeter is a thimble ionization chamber. In the presence of ionizing radiation, a particular quantity of air will be ionized and cause the fiber indicator to register radiation quantity in milliroentgen (mR). The self-reading type may be "read" by holding the dosimeter up to the light and, looking through the eyepiece, observing the fiber indicator, which indicates a quantity of 0 to 200 mR. Although it provides an immediate reading while other personnel monitors require "processing," the disadvantage of the pocket dosimeter is that it does not provide a permanent legal record of exposure.
161487. Which of the following terms is correctly used to describe x-ray beam quality?
1615(A) mA
1616(B) HVL
1617(C) Intensity
1618(D) Dose rate
1619------------------------------ - (B) Kilovoltage (kV) and the HVL effect a change in both the quantity and the quality of the primary beam. The principal qualitative factor of the primary beam is kilovoltage, but an increase in kilovoltage will also increase the number of photons produced at the target. HVL, defined as the amount of material necessary to decrease the intensity of the beam to one-half, therefore changes both beam quality and beam quantity. Milliamperage is directly proportional to x-ray intensity (i.e., quantity/dose rate) but is unrelated to the quality of the beam.
162088. The most efficient type of male gonadal shielding for use during fluoroscopy is
1621(A) flat contact
1622(B) shaped contact (contour)
1623(C) shadow
1624(D) cylindrical
1625------------------------------ - (B) Gonadal shielding should be used whenever appropriate and possible during radiographic and fluoroscopic examinations. Flat contact shields are useful for simple recumbent studies, but when the examination necessitates obtaining oblique, lateral, or erect projections, flat contact shields are easily displaced and become less efficient. Shaped contact (contour) shields are best because they enclose the male reproductive organs and remain in position for oblique, lateral, and erect projections. Shadow shields that attach to the tube head are particularly useful for surgical sterile fields.
162689. Isotopes are atoms that have the same
1627(A) mass number but a different atomic number
1628(B) atomic number but a different mass number
1629(C) atomic number but a different neutron number
1630(D) atomic number and mass number
1631------------------------------ - (B) Isotopes are atoms of the same element (the same atomic number or number of protons) but a different mass number. They differ, therefore, in their number of neutrons. Atoms having the same mass number but different atomic number are isobars. Atoms having the same neutron number but different atomic number are isotones. Atoms with the same atomic number and mass number are isomers.
163290. If the ESE for a particular exposure is 25 mrad, what will be the intensity of the scattered beam perpendicular to and 1 m from the patient?
1633(A) 25 mrad
1634(B) 2.5 mrad
1635(C) 0.25 mrad
1636(D) 0.025 mrad
1637------------------------------ - (D) The patient is the most important radiation scatterer during both radiography and fluoroscopy. In general, at 1 m from the patient, the intensity is reduced by a factor of 1,000 to about 0.1% of the original intensity. Successive scatterings can reduce the intensity to unimportant levels. Calculate that 0.1% of 25 mrad is 0.025 mrad.
163891. The likelihood of adverse radiation effects to any radiographer whose dose is kept below the recommended guideline is
1639(A) very probable
1640(B) possible
1641(C) very remote
1642(D) zero
1643------------------------------ - (C) The likelihood of radiation effects to occupationally exposed individuals whose dose is kept below the recommended limits is very remote. Exposure to ionizing radiation always carries some risk, but studies have indicated that the risk is a very small one if established guidelines are followed. Potential hazards must be understood and proper precautions taken.
164492. Factors that contribute to the amount of scattered radiation produced include
16451. radiation quality
16462. field size
16473. grid ratio
1648(A) 1 only
1649(B) 1 and 2 only
1650(C) 2 and 3 only
1651(D) 1, 2, and 3
1652------------------------------ - (B) The amount of scattered radiation produced depends first on the kilovoltage (beam quality) selected; the higher the kilovolts peak, the more scattered radiation is produced. The size of the irradiated field also has a great deal to do with the amount of scattered radiation produced; the larger the field size, the greater is the amount of scattered radiation. Thickness and condition of tissue also are important considerations; the thicker and/or more dense the tissue, the more scatter is produced. If the condition of the tissue is such that pathology makes it more difficult to penetrate, more scattered radiation will be produced. Grid ratio has no effect on the amount of scattered radiation produced but does significantly impact the amount of scattered radiation reaching the IR.
165393. The SSD in mobile fluoroscopy must be
1654(A) a minimum of 15 in.
1655(B) a maximum of 15 in.
1656(C) a minimum of 12 in.
1657(D) a maximum of 12 in.
1658------------------------------ - (C) Lead and distance are the two most important ways to protect from radiation exposure. Fluoroscopy can be particularly hazardous because the source-to-skin distance (SSD) is so much shorter than in overhead radiography. Therefore, it has been established that fixed (stationary) and mobile fluoroscopic equipment must provide at least 12 in. (30 cm) of SSD for protection of the patient.
165994. The automatic exposure device that is located immediately under the x-ray table is the
1660(A) ionization chamber
1661(B) scintillation camera
1662(C) photomultiplier
1663(D) photocathode
1664------------------------------ - (A) Automatic exposure control (AEC) devices are used in today's equipment and serve to produce consistent and comparable radiographic results. In one type of AEC, there is an ionization chamber just beneath the tabletop above the cassette. The part to be examined is centered on it (the sensor) and radiographed. When a predetermined quantity of ionization has occurred (equal to the correct density), the exposure terminates automatically. In the other type of AEC, the phototimer/photomultiplier, a small fluorescent screen is positioned beneath the cassette. When remnant radiation emerging from the patient exposes the IR and exits the cassette, the fluorescent screen emits light. Once a predetermined amount of fluorescent light is "seen" by the photocell sensor, the exposure is terminated. A scintillation camera is used in nuclear medicine. A photocathode is an integral part of the image intensification system.
166595. The law of Bergonié and Tribondeau states that cells are more radiosensitive if they are
16661. highly proliferative
16672. highly differentiated
16683. immature
1669(A) 1 only
1670(B) 1 and 2 only
1671(C) 1 and 3 only
1672(D) 1, 2, and 3
1673------------------------------ - (C) Bergonié and Tribondeau were French scientists who, in 1906, theorized what has now become verified law. Cells are more radiosensitive if they are immature (undifferentiated or stem) cells, if they are highly mitotic (having a high rate of proliferation), and if the irradiated tissue is young. Cells and tissues that are still undergoing development are more radiosensitive than fully developed tissues.
167496. It is necessary to question a female patient of childbearing age regarding her
16751. date of last menstrual period
16762. possibility of being pregnant
16773. age at her first pregnancy
1678(A) 1 only
1679(B) 1 and 2 only
1680(C) 1 and 3 only
1681(D) 2 and 3 only
1682------------------------------ - (B) It is our ethical responsibility to minimize radiation exposure to ourselves and our patients, particularly during early pregnancy. One way to do this is to inquire about the possibility of our female patients being pregnant or for the date of their last menstrual period (to determine the possibility of irradiating a newly fertilized ovum). The safest time for a woman of childbearing age to have elective radiographic examinations is during the first 10 days following the onset of menstruation.
168398. What is the effect on RBE as LET increases?
1684(A) As LET increases, RBE increases.
1685(B) As LET increases, RBE decreases.
1686(C) As LET increases, RBE stabilizes.
1687(D) LET has no effect on RBE.
1688------------------------------ - (A) LET expresses the rate at which photon or particulate energy is transferred to (absorbed by) biologic material (through ionization processes); it depends on the type of radiation and the characteristics of the absorber. RBE describes the degree of response or amount of biologic change one can expect of the irradiated material. As the amount of transferred energy (LET) increases (from interactions occurring between radiation and biologic material), the amount of biologic effect/damage will also increase.
168999. Which of the following would most likely result in the greatest skin dose?
1690(A) Short SID
1691(B) High kVp
1692(C) Increased filtration
1693(D) Increased mA
1694------------------------------ - (A) The shorter the SID, the greater is the skin dose. That is why there are specific SSD restrictions in fluoroscopy. High kilovolt peak produces more penetrating photons, thereby decreasing skin dose. Filtration is used to remove the low-energy photons from the primary beam, which contribute to skin dose.
1695100. Which of the following radiation-induced conditions is most likely to have the longest latent period?
1696(A) Leukemia
1697(B) Temporary infertility
1698(C) Erythema
1699(D) Acute radiation lethality
1700------------------------------ - (A) Radiation effects that appear days or weeks following exposure (early effects) are in response to relatively high radiation doses. These should never occur in diagnostic radiology today; they occur only in response to doses much greater than those used in diagnostic radiology. One of the effects that may be noted in such a circumstance is the hematologic effect—reduced numbers of white blood cells, red blood cells, and platelets in the circulating blood. Immediate local tissue effects can include effects on the gonads (i.e., temporary infertility) and on the skin (e.g., epilation and erythema). Acute radiation lethality, or radiation death, occurs after an acute exposure and results in death in weeks or days. Radiation-induced malignancy, leukemia, and genetic effects are late effects (or stochastic effects) of radiation exposure. These can occur years after survival of an acute radiation dose or after exposure to low levels of radiation over a long period of time. Radiation workers need to be especially aware of the late effects of radiation because their exposure to radiation is usually low level over a long period of time. Occupational radiation protection guidelines, therefore, are based on late effects of radiation according to a linear, nonthreshold dose-response curve.
1701101. Which of the following ionizing radiations is described as having an RBE of 1.0?
1702(A) 10 MeV protons
1703(B) 5 MeV alpha particles
1704(C) Diagnostic x-rays
1705(D) Fast neutrons
1706------------------------------ - (C) LET increases with the ionizing potential of the radiation; for example, alpha particles are more ionizing than x-radiation, and, therefore, they have a higher LET. As ionizations and LET increase, there is greater possibility of an effect on living tissue; therefore, the RBE increases. The RBE [sometimes called quality factor (QF)] of diagnostic x-rays is 1, the RBE of fast neutrons is 10, the RBE of 5-MeV alpha particles is 20, and the RBE of 10-MeV protons is 5.0.
1707102. If an individual receives 50 mR while standing 4 ft from a source of radiation for 2 minutes, which of the following option(s) will most effectively reduce his or her radiation exposure to that source of radiation?
1708(A) Standing 3 ft from the source for 2 minutes
1709(B) Standing 8 ft from the source for 2 minutes
1710(C) Standing 5 ft from the source for 1 minute
1711(D) Standing 6 ft from the source for 2 minutes
1712------------------------------ - (B) A quick survey of the distractors reveals that option (A) will increase exposure dose and thus is eliminated as a possible correct answer. Options (B), (C), and (D) will serve to reduce radiation exposure because in each case either time is decreased or distance is increased. It remains to be seen, then, which is the more effective. Using the inverse-square law of radiation, at a distance of 8 ft, the individual will receive 12.5 mR in 2 minutes (double distance from source = one-fourth the original intensity).
1713103. The most radiosensitive portion of the GI tract is the
1714(A) upper esophagus
1715(B) stomach
1716(C) small bowel
1717(D) cecum and ascending colon
1718------------------------------ - (C) The most radiosensitive portion of the GI tract is the small bowel. Projecting from the lining of the small bowel are villi, from the intestinal crypt cells of Lieberkühn, which are responsible for the absorption of nutrients into the bloodstream. Because the cells of the villi are continually being cast off, new cells must continually arise from the crypts of Lieberkühn. Being highly mitotic undifferentiated stem cells, they are very radiosensitive. Thus, the small bowel is the most radiosensitive portion of the GI tract.
1719104. How do fractionation and protraction affect radiation dose effects?
17201. They reduce the effect of radiation exposure.
17212. They permit cellular repair.
17223. They allow tissue recovery.
1723(A) 1 only
1724(B) 1 and 2 only
1725(C) 2 and 3 only
1726(D) 1, 2, and 3
1727------------------------------ - (D) Fractionation and protraction influence the effect of radiation on tissue. Larger quantities, of course, increase tissue effect. The energy (i.e., quality and penetration) of the radiation determines whether the effects will be superficial (erythema) or deep (organ dose). Certain tissues (such as blood-forming organs and the gonads) are more radiosensitive than others (such as muscle and nerve). If the dose is delivered in portions (fractionation) and/or delivered over a length of time (protraction), the less the tissue effects.
1728105. The photoelectric effect is an interaction between an x-ray photon and
1729(A) an inner-shell electron
1730(B) an outer-shell electron
1731(C) a nucleus
1732(D) another photon
1733------------------------------ - (A) In the photoelectric effect, a relatively low-energy incident photon uses all its energy to eject an inner-shell electron, leaving a vacancy. An electron from the next shell will drop to fill the vacancy, and a characteristic ray is given up in the transition. This type of interaction is more harmful to the patient because all the photon energy is transferred to tissue.
1734106. Filters used in radiographic x-ray tubes generally are composed of
1735(A) aluminum
1736(B) copper
1737(C) tin
1738(D) lead
1739------------------------------ - (A) Filters are used in radiography to remove soft (low-energy) radiation that contributes only to patient dose. The filters usually are made of aluminum. Equipment operating above 70 kVp must have total filtration of 2.5 mm Al equivalent (inherent + added).
1740107. All the following function to reduce patient dose except
1741(A) beam restriction
1742(B) high kVp, low mAs factors
1743(C) a high-speed grid
1744(D) a high-speed imaging system
1745------------------------------ - (C) The use of a grid requires an increase in milliampere-seconds and, therefore, patient dose; the higher the grid ratio, the greater is the increase in milliampere-seconds required. Collimation (beam restriction) restricts the amount of tissue being irradiated and, therefore, reduces patient dose. High kilovoltage reduces the amount of radiation absorbed by the patient's tissues (recall the photoelectric effect), and low milliampere-seconds reduces the quantity of radiation delivered to the patient. The higher the speed of the imaging system (e.g., film-screen combination), the less are the required milliampere-seconds.
1746108. In the production of Bremsstrahlung radiation
1747(A) the incident photon ejects an inner-shell tungsten electron
1748(B) the incident photon is deflected, with resulting energy loss
1749(C) the incident electron ejects an inner-shell tungsten electron
1750(D) the incident electron is deflected, with resulting energy loss
1751------------------------------ - (D) Bremsstrahlung (or Brems) radiation is one of the two kinds of x-rays produced at the tungsten target of the x-ray tube during interaction between high-speed electrons coming from the filament and the anodes' tungsten atoms. The incident high-speed electron, passing through a tungsten atom, is attracted by the positively charged nucleus and, therefore, is deflected from its course, with a resulting loss of energy. This energy is given up in the form of an x-ray photon.
1752109. An increase in total filtration of the x-ray beam will increase
1753(A) patient skin dose
1754(B) beam HVL
1755(C) image contrast
1756(D) milliroentgen (mR) output
1757------------------------------ - (B) Aluminum filters are used to decrease patient skin dose by absorbing the low-energy photons (therefore, decreased milliroentgen output) that do not contribute to the image but do contribute to patient skin dose. HVL is defined as that thickness of any absorber that will decrease the intensity of a particular beam to one-half its original value. As filtration of an x-ray beam is increased, the overall average energy of the resulting beam is greater (because the low-energy photons have been removed)—and, therefore, the HVL thickness required would be greater.
1758110. Which of the following is considered the unit of exposure in air?
1759(A) Roentgen (C/kg)
1760(B) Rad (Gy)
1761(C) Rem (Sv)
1762(D) RBE
1763------------------------------ - (A) The roentgen measures ionization in air and is referred to as the unit of exposure. Rad is an acronym for radiation absorbed dose, and rem is an acronym for radiation-equivalent man. RBE is used to determine biologic damage in living tissue.
1764111. The purpose of filters in a film badge is
1765(A) to eliminate harmful rays
1766(B) to measure radiation quality
1767(C) to prevent exposure by alpha particles
1768(D) as a support for the film contained within
1769------------------------------ - (B) The filters (usually aluminum and copper) serve to help measure radiation quality (i.e., energy). Only the most energetic radiation will penetrate the copper; radiation of lower levels of energy will penetrate the aluminum, and the lowest energy radiation will pass readily through the unfiltered area. Thus, radiation of different energy levels can be recorded, measured, and reported.
1770112. How many HVLs are required to reduce the intensity of a beam of monoenergetic photons to less than 15% of its original value?
1771(A) 2
1772(B) 3
1773(C) 4
1774(D) 5
1775------------------------------ - (B) An HVL may be defined as the amount and thickness of absorber necessary to reduce the radiation intensity to half its original value. Thus, the first HVL would reduce the intensity to 50% of its original value, the second to 25%, the third to 12.5%, and the fourth to 6.25% of its original value.
1776113. Which of the following has (have) an effect on the amount and type of radiation-induced tissue damage?
17771. Quality of radiation
17782. Type of tissue being irradiated
17793. Fractionation
1780(A) 1 only
1781(B) 1 and 2 only
1782(C) 1 and 3 only
1783(D) 1, 2, and 3
1784------------------------------ - (D) All the factors listed influence the effect of radiation on tissue. Larger quantities, of course, increase radiation's effect on tissue. The energy (i.e., quality and penetration) of the radiation determines whether the effects will be superficial (erythema) or deep (organ dose). Certain tissues (such as blood-forming organs and the gonads) are more radiosensitive than others (such as muscle and nerve). The length of time over which the exposure is spread (fractionation) is important; the longer the period of time, the less are the tissue effects.
1785114. Radiation dose to personnel is reduced by which of the following exposure control cord guidelines?
17861. Exposure cords on fixed equipment must be very short.
17872. Exposure cords on mobile equipment should be fairly long.
17883. Exposure cords on fixed and mobile equipment should be of the coiled, expandable type.
1789(A) 1 only
1790(B) 1 and 2 only
1791(C) 2 and 3 only
1792(D) 1, 2, and 3
1793------------------------------ - (B) Radiographic and fluoroscopic equipment is designed to help decrease the exposure dose to patient and operator. One of the design features is the exposure cord. Exposure cords on fixed equipment must be short enough to prevent the exposure from being made outside the control booth. Exposure cords on mobile equipment must be long enough to permit the operator to stand at least 6 ft from the x-ray tube.
1794115. Any wall that the useful x-ray beam can be directed toward is called a
1795(A) secondary barrier
1796(B) primary barrier
1797(C) leakage barrier
1798(D) scattered barrier
1799------------------------------ - (B) Protective barriers are classified as either primary or secondary. Primary barriers protect from the useful, or primary, x-ray beam and consist of a certain thickness of lead. They are located anywhere that the primary beam can possibly be directed, for example, the walls of the x-ray room. The walls of the x-ray room usually require a 1/16-in. (1.5-mm) thickness of lead and should be 7 ft high. Secondary barriers protect from secondary (scattered and leakage) radiation. Secondary barriers are control booths, lead aprons, gloves, and the wall of the x-ray room above 7 ft. Secondary barriers require much less lead than primary barriers.
1800116. Which of the following body parts is (are) included in whole-body dose?
18011. Gonads
18022. Blood-forming organs
18033. Extremities
1804(A) 1 only
1805(B) 1 and 2 only
1806(C) 1 and 3 only
1807(D) 1, 2, and 3
1808------------------------------ - (B) Whole-body dose is calculated to include all the especially radiosensitive organs. The gonads and the blood-forming organs are particularly radiosensitive. Some body parts, such as the skin and extremities, have a higher annual dose limit.
1809117. Which of the following projections would deliver the largest thyroid dose?
1810(A) AP skull
1811(B) PA skull
1812(C) PA esophagus
1813(D) PA chest
1814------------------------------ - (A) Exposure dose to patients can be expressed as entrance skin exposure (ESE), sometimes referred to as skin entrance exposure (SEE). Exposure can also be expressed in terms of organ dose. Organ doses to the gonads, bone marrow, breast, thyroid, lens, and lung can be determined. Patient position and beam restriction often make a significant difference in patient dose. Examinations performed PA, rather than AP, often decrease exposure to sensitive organs. This is so because the lower energy x-ray photons will be absorbed by the anatomic structures closer to the x-ray source, and the higher energy photons will penetrate and exit the part (penetrating the sensitive part rather than being absorbed by it). PA abdomen radiographs deliver less quantity dose to the reproductive organs than do AP abdomen radiographs. An AP skull projection (80 kVp) delivers about 90 mrad to the thyroid, whereas a PA skull (80 kVp) radiograph delivers 8 mrad; the PA esophagus (110 kVp) radiograph delivers 9 mrad, and the PA chest (120 kVp) radiograph delivers about 1 mrad.
1815118. Which of the following personnel monitoring devices used in diagnostic radiography is considered to be the most sensitive and accurate?
1816(A) TLD
1817(B) Film badge
1818(C) OSL dosimeter
1819(D) Pocket dosimeter
1820------------------------------ - (C) Ionization is the fundamental principle of operation of both the film badge and the pocket dosimeter. In the film badge, the film's silver halide emulsion is ionized by x-ray photons. The pocket dosimeter contains an ionization chamber, and the number of ionizations taking place may be equated to exposure dose; it is accurate, but it is used only to detect larger amounts of radiation exposure. The TLD can measure exposures as low as 5 mrem, whereas film badges will measure a minimum exposure only as low as 10 mrem. TLDs contain lithium fluoride crystals that undergo characteristic changes on irradiation. When the crystals are subsequently heated, they emit a quantity of visible (thermo) luminescence/light in proportion to the amount of radiation absorbed. The relatively new OSL dosimeters contain aluminum oxide crystals that also undergo characteristic changes on irradiation. When the Al2O3 crystals are stimulated by a laser, they emit (optically stimulated) luminescence/light in proportion to the amount of radiation absorbed. OSL dosimeters can measure exposures as low as 1 mrem.
1821119. Irradiation of macromolecules in vitro can result in
18221. main-chain scission
18232. cross-linking
18243. point lesions
1825(A) 1 only
1826(B) 1 and 2 only
1827(C) 2 and 3 only
1828(D) 1, 2, and 3
1829------------------------------ - (D) Irradiation damage is a result of either the effects of irradiation on water (radiolysis) or its effects on macromolecules. Effects on macromolecules include main-chain scission, cross-linking, and point lesions. Main-chain scission breaks the DNA molecule into two or more pieces. Cross-linking is incorrect joining of broken DNA fragments. A point lesion is the disruption of a single chemical bond as a result of irradiation. Because 80% of the body is made up of water, radiolysis of water is the predominant radiation interaction in the body.
1830120. Which of the following radiation situations is potentially the most harmful?
1831(A) A large dose to a specific area all at once
1832(B) A small dose to the whole body over a period of time
1833(C) A large dose to the whole body all at one time
1834(D) A small dose to a specific area over a period of time
1835------------------------------ - (C) The greatest effect-response from irradiation is brought about by a large dose of radiation to the whole body delivered all at one time. Whole-body radiation can depress many body functions. With a fractionated dose, the effects would be less severe because the body would have an opportunity to repair between doses.
1836121. How much protection is provided from a 100-kVp x-ray beam when using a 0.50-mm lead-equivalent apron?
1837(A) 40%
1838(B) 75%
1839(C) 88%
1840(D) 99%
1841------------------------------ - (B) Lead aprons are worn by occupationally exposed individuals during fluoroscopic procedures. Lead aprons are available with various lead equivalents; 0.25, 0.5, and 1.0 mm of lead are the most common. The 1.0-mm lead equivalent apron will provide close to 100% protection at most kilovoltage levels, but it is rarely used because it weighs anywhere from 12 to 24 lb. A 0.25-mm lead-equivalent apron will attenuate about 97% of a 50-kVp x-ray beam, 66% of a 75-kVp beam, and 51% of a 100-kVp beam. A 0.5-mm apron will attenuate about 99% of a 50-kVp beam, 88% of a 75-kVp beam, and 75% of a 100-kVp beam.
1842122. Occupational radiation monitoring is required when it is likely that an individual will receive more than what fraction of the annual dose limit?
1843(A) ½
1844(B) ¼
1845(C) 1/10
1846(D) 1/40
1847------------------------------ - (C) Different types of monitoring devices are available for the occupationally exposed, and anyone who might receive more than one-tenth the annual dose limit must be monitored. Ionization is the fundamental principle of operation of both the film badge and the pocket dosimeter. In the film badge, the film's silver halide emulsion is ionized by x-ray photons. The pocket dosimeter contains an ionization chamber (containing air), and the number of ions formed (of either sign) is equated to exposure dose. TLDs are radiation monitors that use lithium fluoride crystals. Once exposed to ionizing radiation and then heated, these crystals give off light proportional to the amount of radiation received. OSL dosimeters are radiation monitors that use aluminum oxide crystals. These crystals, once exposed to ionizing radiation and then subjected to a laser, give off luminescence proportional to the amount of radiation received.
1848124. Examples of late effects of ionizing radiation on humans include
18491. leukemia
18502. local tissue damage
18513. malignant disease
1852(A) 1 only
1853(B) 1 and 2 only
1854(C) 1 and 3 only
1855(D) 1, 2, and 3
1856------------------------------ - (D) Occupationally exposed individuals are concerned principally with late (i.e., long-term or delayed) effects of ionizing radiation such as radiation-induced genetic effects, leukemia, and cancers (e.g., bone, lung, thyroid, and breast), as well as local effects, such as skin erythema, infertility, and cataracts—these can occur many years following initial exposure to low levels of ionizing radiation. The long-term/delayed effects usually are chronic, and many are represented by the linear, non-threshold dose-response curve.
1857125. Which of the following cells are the most radiosensitive?
1858(A) Myelocytes
1859(B) Erythroblasts
1860(C) Megakaryocytes
1861(D) Myocytes
1862------------------------------ - (B) Bergonié and Tribondeau theorized in 1906 that all precursor cells are particularly radiosensitive (e.g., stem cells found in bone marrow). There are several types of stem cells in bone marrow, and the different types differ in degree of radiosensitivity. Of these, red blood cell precursors, or erythroblasts, are the most radiosensitive. White blood cell precursors, or myelocytes, follow. Platelet precursor cells, or megakaryocytes, are the least radiosensitive. Myocytes are mature muscle cells that are fairly radioresistant.
1863126. Which of the following statements regarding the pregnant radiographer is (are) true?
18641. She should declare her pregnancy to her supervisor.
18652. She should be assigned a second personnel monitor.
18663. Her radiation history should be reviewed.
1867(A) 1 only
1868(B) 1 and 2 only
1869(C) 2 and 3 only
1870(D) 1, 2, and 3
1871------------------------------ - (D) The pregnant radiographer should declare her pregnancy to her supervisor; at that time, her radiation exposure history can be reviewed and appropriate assignments made. Special arrangements are required for occupational monitoring of the pregnant radiographer. The pregnant radiographer will wear two dosimeters—one in its usual place at the collar and the other, a baby/fetal dosimeter, worn over the abdomen and under the lead apron during fluoroscopy. The baby/fetal dosimeter must be identified as such and always must be worn in the same place. Care must be taken not to mix the positions of the two dosimeters. The dosimeters are read monthly as usual.
1872127. What is (are) the major effect(s) of deoxyribonucleic acid (DNA) irradiation?
18731. Malignant disease
18742. Chromosome aberration
18753. Cell death
1876(A) 1 only
1877(B) 1 and 2 only
1878(C) 2 and 3 only
1879(D) 1, 2, and 3
1880------------------------------ - (D) Chromosome aberration, cell death, and malignant disease are major effects of DNA irradiation, often as a result of abnormal metabolic activity. If the damage happens to the DNA of a germ cell, the radiation response may not occur until one or more generations later.
1881128. Which of the following contributes most to patient dose?
1882(A) The photoelectric effect
1883(B) Compton scatter
1884(C) Classic scatter
1885(D) Thompson scatter
1886------------------------------ - (A) In the photoelectric effect, a relatively low-energy photon uses all its energy to eject an inner-shell electron, leaving a vacancy. An electron from the shell above drops down to fill the vacancy and in so doing emits a characteristic ray. This type of interaction is most harmful to the patient because all the photon energy is transferred to tissue. In Compton scatter, a high-energy incident photon uses some of its energy to eject an outer-shell electron. In so doing, the incident photon is deflected with reduced energy but usually retains most of its energy and exits the body as an energetic scattered ray. The scattered radiation will either contribute to image fog or pose a radiation hazard to personnel depending on its direction of exit. In classic scatter, a low-energy photon interacts with an atom but causes no ionization; the incident photon disappears in the atom and then reappears immediately and is released as a photon of identical energy but with changed direction. Thompson scatter is another name for classic scatter.
1887130. The classifications of acute radiation syndrome include all the following except
1888(A) central nervous system
1889(B) gastrointestinal
1890(C) neonatal
1891(D) hematologic
1892------------------------------ - (C) Early somatic effects are manifested within minutes, hours, days, or weeks of irradiation and occur only following a very large dose of ionizing radiation. It must be emphasized that doses received from diagnostic radiologic procedures are not sufficient to produce these early effects. An exceedingly high dose of radiation delivered to the whole body in a short period of time is required to produce early somatic effects. These whole-body responses are grouped into three categories—reflecting the system(s) affected and the resulting symptoms: hematologic, gastrointestinal, and central nervous system.
1893131. In the production of characteristic radiation at the tungsten target, the incident electron
1894(A) ejects an inner-shell tungsten electron
1895(B) ejects an outer-shell tungsten electron
1896(C) is deflected, with resulting energy loss
1897(D) is deflected, with resulting energy gain
1898------------------------------ - (A) Characteristic radiation is one of two kinds of x-rays produced at the tungsten target of the x-ray tube. The incident, or incoming, high-speed electron ejects a K-shell tungsten electron. This leaves a hole in the K shell, and an L-shell electron drops down to fill the K vacancy. Because L electrons are at a higher energy level than K-shell electrons, the L-shell electron gives up the difference in binding energy in the form of a photon, a characteristic x-ray (characteristic of the K shell).
1899132. Which of the following defines the gonadal dose that, if received by every member of the population, would be expected to produce the same total genetic effect on that population as the actual doses received by each of the individuals?
1900(A) Genetically significant dose
1901(B) Somatically significant dose
1902(C) Maximum permissible dose
1903(D) Lethal dose
1904------------------------------ - (A) The genetically significant dose (GSD) illustrates that large exposures to a few people are cause for little concern when diluted by the total population. On the other hand, we all share the burden of that radiation received by the total population, especially as the use of medical radiation increases, so each individual's share of the total exposure increases.
1905133. If an exposure dose of 50 mR/h is delivered from a distance of 3 ft, what would be the dose delivered after 20 minutes at a distance of 5 ft from the source?
1906(A) 6 mR
1907(B) 18 mR
1908(C) 46 mR
1909(D) 138 mR
1910------------------------------ - (A) The relationship between x-ray intensity and distance from the source is expressed by the inverse-square law of radiation.
1911134. The term effective dose refers to
1912(A) whole-body dose
1913(B) localized organ dose
1914(C) genetic effects
1915(D) somatic and genetic effects
1916------------------------------ - (A) Every radiographic examination involves an ESE, which can be determined fairly easily. It also involves a gonadal dose and a marrow dose, which, if needed, can be calculated by the radiation physicist. If the ESE of a particular examination were calculated to determine the equivalent whole-body dose, this would be termed the effective dose. For example, the ESE of a PA chest radiograph is approximately 70 mrem, whereas the effective dose is 10 mrem. The effective (whole body) dose is much less because much of the body is not included in the primary beam.
1917135. Which of the following is (are) possible long-term somatic effects of radiation exposure?
19181. Blood changes
19192. Cataractogenesis
19203. Embryologic effects
1921(A) 1 only
1922(B) 1 and 2 only
1923(C) 2 and 3 only
1924(D) 1, 2, and 3
1925------------------------------ - (C) Somatic effects are those induced in the irradiated body. Genetic effects of ionizing radiation are those that may not appear for many years (generations) following exposure. Formation of cataracts or cancer (such as leukemia) and embryologic damage are all possible long-term somatic effects of radiation exposure. A fourth is life-span shortening. Blood changes are generally early effects of exposure to large quantities of ionizing radiation.
1926136. The operation of personal radiation monitoring can be based on stimulated luminescence. Which of the following personal radiation monitors function(s) in that manner?
19271. OSL dosimeter
19282. TLD
19293. Pocket dosimeter
1930(A) 1 only
1931(B) 1 and 2 only
1932(C) 1 and 3 only
1933(D) 1, 2, and 3
1934------------------------------ - (B) Occupationally exposed individuals are required to use devices to record and document the radiation they receive over a given period of time, traditionally 1 month. The most commonly used personal dosimeters are the OSL dosimeter, the TLD, and the film badge. These devices are worn only for documentation of occupational exposure, not for any medical or dental x-rays received as a patient. TLDs are radiation monitors that use lithium fluoride crystals. Once exposed to ionizing radiation and then heated, these crystals give off light proportional to the amount of radiation received. OSL dosimeters are radiation monitors that use aluminum oxide crystals. These crystals, once exposed to ionizing radiation and then subjected to a laser, give off luminescence proportional to the amount of radiation received. The pocket dosimeter contains an ionization chamber (containing air), and the number of ions formed (of either sign) is equated to exposure dose.
1935137. If a patient received 1,400 mrad during a 7-minute fluoroscopic examination, what was the dose rate?
1936(A) 200 rad/min
1937(B) 5 rad/min
1938(C) 2.0 rad/min
1939(D) 0.2 rad/min
1940------------------------------ - (D) A measure 1,400 mrad is equal to 1.4 rad. If 1.4 rad were delivered in 7 minutes, then the dose rate would be 0.2 rad/min
1941138. Biologic material irradiated under hypoxic conditions is
1942(A) more sensitive than when irradiated under oxygenated conditions
1943(B) less sensitive than when irradiated under anoxic conditions
1944(C) less sensitive than when irradiated under oxygenated conditions
1945(D) unaffected by the presence or absence of oxygen
1946------------------------------ - (C) Biologic tissue is more sensitive to radiation when it is in an oxygenated state. A characteristic of many avascular (and, therefore, hypoxic) tumors is their resistance to treatment with radiation. Hyperbaric (high-pressure oxygen) therapy is used in some therapy centers in an effort to increase the sensitivity of the tissues being treated.
1947139. Which interaction between ionizing radiation and the target molecule involves formation of a free radical?
1948(A) Direct effect
1949(B) Indirect effect
1950(C) Target effect
1951(D) Random effect
1952------------------------------ - (B) The principal interactions that occur between x-ray photons and body tissues in the diagnostic x-ray range, the photoelectric effect and Compton scatter, are ionization processes producing photoelectrons and recoil electrons that traverse tissue and subsequently ionize molecules. These interactions occur randomly but can lead to molecular damage in the form of impaired function or cell death. The target theory specifies that DNA molecules are the targets of greatest importance and sensitivity; that is, DNA is the key sensitive molecule. However, since the body is 65% to 80% water, most interactions between ionizing radiation and body cells will involve radiolysis of water rather than direct interaction with DNA. The two major types of effects that occur are the direct effect and the indirect effect. The direct effect usually occurs with high-LET radiations and when ionization occurs at the DNA molecule itself. The indirect effect, which occurs most frequently, happens when ionization takes place away from the DNA molecule in cellular water. However, the energy from the interaction can be transferred to the molecule via a free radical (formed by radiolysis of cellular water).
1953Possible damage to the DNA molecule is diverse. A single main-chain/side-rail scission (break) on the DNA molecule is repairable. A double main-chain/side-rail scission may be repaired with difficulty or may result in cell death. A double main-chain/side-rail scission on the same rung of the DNA ladder results in irreparable damage or cell death. Faulty repair of main-chain breakage can result in cross-linking. Damage to the nitrogenous bases, that is, damage to the base itself or to the rungs connecting the main chains, can result in alteration of base sequences, causing a molecular lesion/point mutation. Any subsequent divisions result in daughter cells with incorrect genetic information.
1954140. The single most important scattering object in both radiography and fluoroscopy is the
1955(A) x-ray table
1956(B) x-ray tube
1957(C) patient
1958(D) IR
1959------------------------------ - (C) The patient, as the first scatterer, is the most important scatterer. At 1 m from the patient, the intensity of the scattered beam is 0.1% of the intensity of the primary beam. Compton scatter emerging from the patient is almost as energetic as the primary beam entering the patient.
1960141. All the following statements regarding TLDs are true except
1961(A) TLDs are reusable
1962(B) a TLD is a personal radiation monitor
1963(C) TLDs use a lithium fluoride phosphor
1964(D) after x-ray exposure, TLDs emit heat in response to stimulation by light
1965------------------------------ - (D) A TLD is a sensitive and accurate device used in radiation dosimetry. It may be used as a personal dosimeter or to measure patient dose during radiographic examinations and therapeutic procedures. The TLD uses a thermoluminescent phosphor, usually lithium fluoride. When used as a personal monitor, the TLD is worn for 1 month. During this time, it stores information regarding the radiation to which it has been exposed. It is then returned to the commercial supplier. In the laboratory, the phosphors are heated. They respond by emitting a particular quantity of light (not heat) that is in proportion to the quantity of radiation delivered to it. After they are cleared of stored information, they are returned for reuse.
1966142. A student radiographer who is under 18 years of age must not receive an annual occupational dose of greater than
1967(A) 0.1 rem (1 mSv)
1968(B) 0.5 rem (5 mSv)
1969(C) 5 rem (50 mSv)
1970(D) 10 rem (100 mSv)
1971------------------------------ - (A) Because the established dose-limit formula guideline is used for occupationally exposed persons 18 years of age and older, guidelines had to be established to cover the event that a student entered the clinical component of a radiography educational program prior to age 18. The guideline states that the occupational dose limit for students under 18 years of age is 0.1 rem (100 mrem or 1 mSv) in any given year.
1972143. What is the approximate ESE for the average AP lumbar spine radiograph?
1973(A) 30 rad
1974(B) 30 mrad
1975(C) 300 rad
1976(D) 300 mrad
1977------------------------------ - (D) Patients occasionally will question the radiographer regarding the amount of radiation they are receiving during their examination. Most of these patients are merely curious because they have heard a recent news report about x-rays or have perhaps studied about x-rays in school recently. It is a good idea for radiographers to have some knowledge of average exposure doses for patients who desire this information. The curious patient also can be referred to the medical physicist for more detailed information. The average AP cervical spine radiograph delivers about 80 mrad (0.080 rad). The average AP supine lumbar spine radiograph delivers an ESE of about 350 mrad (0.35 rad). The average AP supine abdomen radiograph delivers about 300 mrad.
1978144. Which of the following is (are) likely to improve image quality and decrease patient dose?
19791. Beam restriction
19802. Low kilovolt and high microampere-second factors
19813. Grids
1982(A) 1 only
1983(B) 1 and 3 only
1984(C) 2 and 3 only
1985(D) 1, 2, and 3
1986------------------------------ - (A) The use of beam restrictors limits the amount of tissue being irradiated, thus decreasing patient dose and decreasing the production of scattered radiation. High milliampere-second factors increase patient dose. Patient dose is reduced by using high-kilovolt and low-milliampere-second combinations. Although the use of a grid improves image quality by decreasing the amount of scattered radiation reaching the IR, it always requires an increase in exposure factor (usually milliampere-seconds) and, therefore, results in increased patient dose.
1987145. Types of secondary radiation barriers include
19881. the control booth
19892. lead aprons
19903. the x-ray tube housing
1991(A) 2 only
1992(B) 1 and 2 only
1993(C) 2 and 3 only
1994(D) 1, 2, and 3
1995------------------------------ - (D) Secondary radiation includes leakage and scattered radiation. The control booth wall is a secondary barrier; therefore, the primary beam must never be directed toward it. The x-ray tube housing must reduce leakage radiation to less than 100 mR/h at a distance of 1 m from the housing. Lead aprons, lead gloves, portable x-ray barriers, and so on are also designed to protect the user from exposure to scattered radiation and will not protect her or him from the primary beam.
1996146. Lead aprons are worn during fluoroscopy to protect the radiographer from exposure to radiation from
1997(A) the photoelectric effect
1998(B) Compton scatter
1999(C) classic scatter
2000(D) pair production
2001------------------------------ - (B) In the photoelectric effect, a relatively low-energy photon uses all its energy to eject an inner-shell electron, leaving a vacancy. An electron from the shell above drops down to fill the vacancy and in so doing gives up a characteristic ray. This type of interaction is most harmful to the patient because all the photon energy is transferred to tissue. In Compton scatter, a high-energy incident photon ejects an outer-shell electron. The incident photon is deflected with reduced energy, but it usually retains most of its energy and exits the body as an energetic scattered ray. This scattered ray either will contribute to image fog or will pose a radiation hazard to personnel depending on its direction of exit. In classic scatter, a low-energy photon interacts with an atom but causes no ionization; the incident photon disappears into the atom and then is released immediately as a photon of identical energy but with changed direction. Pair production is an interaction that occurs only at energies of 1.02 MeV, and therefore, it does not occur in diagnostic radiography.
2002147. Types of structural damage to a DNA molecule by ionizing radiation include which of the following?
20031. Single-side-rail scission
20042. Double-side-rail scission
20053. Cross-linking
2006(A) 1 only
2007(B) 2 only
2008(C) 1 and 2 only
2009(D) 1, 2, and 3
2010------------------------------ - (D) The principal interactions that occur between x-ray photons and body tissues in the diagnostic x-ray range, the photoelectric effect and Compton scatter, are ionization processes producing photoelectrons and recoil electrons that traverse tissue and subsequently ionize molecules. These interactions occur randomly but can lead to molecular damage in the form of impaired function or cell death. The target theory specifies that DNA molecules are the targets of greatest importance and sensitivity; that is, DNA is the key sensitive molecule. However, since the body is 65% to 80% water, most interactions between ionizing radiation and body cells will involve radiolysis of water rather than direct interaction with DNA. The two major types of effects that occur are the direct effect and the indirect effect. The direct effect usually occurs with high-LET radiations and when ionization occurs at the DNA molecule itself. The indirect effect, which occurs most frequently, happens when ionization takes place away from the DNA molecule in cellular water. However, the energy from the interaction can be transferred to the molecule via a free radical (formed by radiolysis of cellular water).
2011Possible damage to the DNA molecule is diverse. A single main-chain/side-rail scission (break) on the DNA molecule is repairable. A double main-chain/side-rail scission may be repaired with difficulty or may result in cell death. A double main-chain/side-rail scission on the same rung of the DNA ladder results in irreparable damage or cell death. Faulty repair of main-chain breakage can result in cross-linking. Damage to the nitrogenous bases, that is, damage to the base itself or to the rungs connecting the main chains, can result in alteration of base sequences, causing a molecular lesion/point mutation. Any subsequent divisions result in daughter cells with incorrect genetic information.
2012148. Which of the following can be an effective means of reducing radiation exposure?
20131. Barriers
20142. Distance
20153. Time
2016(A) 1 only
2017(B) 2 only
2018(C) 1 and 2 only
2019(D) 1, 2, and 3
2020------------------------------ - (D) As the amount of time one spends in a controlled area decreases, radiation exposure should decrease. Radiation exposure is affected considerably by one's proximity to the radiation source, as defined by the inverse-square law. Barriers (shielding) are an effective means of reducing radiation exposure; primary barriers, such as walls, protect one from the primary beam, and secondary barriers, such as lead aprons, are used to protect one from secondary radiation.
2021149. The effects of radiation on biologic material depend on several factors. If a large quantity of radiation is delivered to a body over a short period of time, the effect
2022(A) will be greater than if it were delivered in increments
2023(B) will be less than if it were delivered in increments
2024(C) has no relation to how it is delivered in time
2025(D) solely depends on the radiation quality
2026------------------------------ - (A) The effects of a quantity of radiation delivered to a body depend on a few factors, including the amount of radiation received, the size of the irradiated area, and how the radiation is delivered in time. If the radiation is delivered in portions over a period of time, it is said to be fractionated and has a less harmful effect than if the radiation were delivered all at once. Cells have an opportunity to repair, and some recovery occurs between doses.
2027150. Somatic effects of radiation refer to effects that are manifested
2028(A) in the descendants of the exposed individual
2029(B) during the life of the exposed individual
2030(C) in the exposed individual and his or her descendants
2031(D) in the reproductive cells of the exposed individual
2032------------------------------ - (B) Somatic effects of radiation refer to those effects experienced directly by the exposed individual, such as erythema, epilation, and cataracts. Genetic effects of radiation exposure are caused by irradiation of the reproductive cells of the exposed individual and are transmitted from one generation to the next.
2033151. What minimum total amount of filtration (inherent plus added) is required in x-ray equipment operated above 70 kVp?
2034(A) 2.5 mm Al equivalent
2035(B) 3.5 mm Al equivalent
2036(C) 2.5 mm Cu equivalent
2037(D) 3.5 mm Cu equivalent
2038------------------------------ - (A) The x-ray tube's glass envelope and oil coolant are considered inherent (built-in) filtration. Thin sheets of aluminum are added to make a total of at least 2.5 mm Al-equivalent filtration in equipment operated above 70 kVp. This is done to remove the low-energy photons that serve only to contribute to patient skin dose.
2039152. The dose of radiation that will cause a noticeable skin reaction is referred to as the
2040(A) LET
2041(B) SSD
2042(C) SED
2043(D) SID
2044------------------------------ - (C) Erythema is the reddening of skin as a result of exposure to large quantities of ionizing radiation. It was one of the first somatic responses to irradiation demonstrated to the early radiology pioneers. The effects of radiation exposure to the skin follow a nonlinear, threshold dose-response relationship. An individual's response to skin irradiation depends on the dose received, the period of time over which it was received, the size of the area irradiated, and the individual's sensitivity. The dose that it takes to bring about a noticeable erythema is referred to as the SED.
2045153. The NCRP recommends an annual effective occupational dose-equivalent limit of
2046(A) 2.5 rem (25 mSv)
2047(B) 5 rem (50 mSv)
2048(C) 10 rem (100 mSv)
2049(D) 20 rem (200 mSv)
2050------------------------------ - (B) In the past few decades, ICRP and NCRP studies have indicated that radiation-induced cancer risks are greater than radiation-induced genetic risks—contrary to previous thought. Their philosophy then grew to be concerned with the probability of radiation-induced cancer mortality in the occupational radiation industry in comparison with annual accidental mortality in "safe" (radiation-free) industries. The NCRP reexamined its 1987 recommendations, and in NCRP Report No. 116, it reiterates its annual effective occupational dose limit as 50 mSv (5 rem).
2051154. Some patients, such as infants and children, are unable to maintain the necessary radiographic position without assistance. If mechanical restraining devices cannot be used, which of the following should be requested or permitted to hold the patient?
2052(A) Transporter
2053(B) Patient's father
2054(C) Patient's mother
2055(D) Student radiographer
2056------------------------------ - (B) If mechanical restraint is impossible, a friend or relative accompanying the patient should be requested to hold the patient. If a parent is to perform this task, it is preferable to elect the father so as to avoid the possibility of subjecting a newly fertilized ovum to even scattered radiation. If a friend or relative is not available, a nurse or transporter may be asked for help. Protective apparel, such as lead apron and gloves, must be provided to the person(s) holding the patient. Radiology personnel must never assist in holding patients, and the individual assisting must never be in the path of the primary beam.
2057155. A controlled area is defined as one
20581. that is occupied by people trained in radiation safety
20592. that is occupied by people who wear radiation monitors
20603. whose occupancy factor is 1
2061(A) 1 and 2 only
2062(B) 2 only
2063(C) 1 and 3 only
2064(D) 1, 2, and 3
2065------------------------------ - (D) A controlled area is one that is occupied by radiation workers who are trained in radiation safety and who wear radiation monitors. The exposure rate in a controlled area must not exceed 100 mR/week; its occupancy factor is considered to be 1, indicating that the area may always be occupied and, therefore, requires maximum shielding. An uncontrolled area is one occupied by the general population; the exposure rate there must not exceed 10 mR/week. Shielding requirements vary according to several factors, one being occupancy factor.
2066156. Which of the following terms refers to the period between conception and birth?
2067(A) Gestation
2068(B) Congenital
2069(C) Neonatal
2070(D) In vitro
2071------------------------------ - (A) The length of time from conception to birth, that is, pregnancy, is referred to as gestation. The term congenital refers to a condition existing at birth. Neonatal relates to the time immediately after birth and the first month of life. In vitro refers to something living outside a living body (as in a test tube), as opposed to in vivo (within a living system).
2072157. Somatic effects resulting from radiation exposure can
20731. have possible consequences on the exposed individual
20742. have possible consequences on future generations
20753. cause temporary infertility
2076(A) 1 only
2077(B) 1 and 3 only
2078(C) 2 and 3 only
2079(D) 1, 2, and 3
2080------------------------------ - (B) It is well established that sufficient quantities of ionizing radiation can cause a number of serious somatic and/or genetic effects. Somatic effects of radiation are those that affect the irradiated body itself. Somatic effects are described as being early or late depending on the length of time between irradiation and manifestation of effects. The human reproductive organs are particularly radiosensitive. Fertility and heredity are greatly affected by the germ cells produced within the testes (spermatogonia) and ovaries (oogonia). Excessive radiation exposure to the gonads can cause temporary or permanent infertility and/or genetic mutations. Infertility is somatic because it affects the exposed individual; genetic mutations affect future generations.
2081158. How does the use of rare earth intensifying screens contribute to lowering the patient dose?
20821. It permits the use of lower milliampere-seconds.
20832. It permits the use of lower kilovolts peak (kVp).
20843. It eliminates the need for patient shielding.
2085(A) 1 only
2086(B) 1 and 2 only
2087(C) 1 and 3 only
2088(D) 2 and 3 only
2089------------------------------ - (A) The faster the intensifying screens used, the fewer are the required milliampere-seconds. Decreasing the intensity (i.e., mAs or quantity) of photons significantly contributes to reducing total patient dose. Decreasing the kilovoltage would increase patient dose because the primary beam would be made up of fewer penetrating photons, so the milliampere-seconds would have to be increased. The importance of patient shielding is never diminished.
2090159. In which type of monitoring device do photons release electrons by their interaction with air?
2091(A) Film badge
2092(B) TLD
2093(C) Pocket dosimeter
2094(D) OSL dosimeter
2095------------------------------ - (C) Different types of monitoring devices are available for the occupationally exposed. Ionization is the fundamental principle of operation of both the film badge and the pocket dosimeter. In the film badge, the film's silver halide emulsion is ionized by x-ray photons. The pocket dosimeter contains an ionization chamber (containing air), and the number of ions formed (of either sign) is equated to exposure dose. TLDs are radiation monitors that use lithium fluoride crystals. Once exposed to ionizing radiation and then heated, these crystals give off light proportional to the amount of radiation received. OSL dosimeters are radiation monitors that use aluminum oxide crystals. These crystals, once exposed to ionizing radiation and then subjected to a laser, give off luminescence proportional to the amount of radiation received.
2096160. The advantages of beam restriction include which of the following?
20971. Less scattered radiation is produced.
20982. Less biologic material is irradiated.
20993. Less total filtration will be necessary.
2100(A) 1 only
2101(B) 1 and 2 only
2102(C) 2 and 3 only
2103(D) 1, 2, and 3
2104------------------------------ - (B) With greater beam restriction, less biologic material is irradiated, thereby reducing the possibility of harmful effects. If less tissue is irradiated, less scattered radiation is produced, resulting in improved IR contrast. The total filtration is not a function of beam restriction but rather is a radiation protection guideline aimed at reducing patient skin dose.
2105161. The person responsible for ascertaining that all radiation guidelines are adhered to and that personnel understand and employ radiation safety measures is the
2106(A) radiology department manager
2107(B) radiation safety officer
2108(C) chief radiologist
2109(D) chief technologist
2110------------------------------ - (B) Radiation safety guidelines are valuable only if they are followed by radiation personnel. The radiation safety officer (RSO) is responsible for being certain that established guidelines are enforced and that personnel understand and employ radiation safety measures to protect themselves and their patients. The RSO is also responsible for performing routine equipment checks to ensure that all equipment meet radiation safety standards.
2111162. The dose-response curve that appears to be valid for genetic and some somatic effects is the
21121. linear
21132. nonlinear
21143. nonthreshold
2115(A) 1 only
2116(B) 1 and 3 only
2117(C) 2 and 3 only
2118(D) 1, 2, and 3
2119------------------------------ - (B) The genetic effects of radiation and some somatic effects, such as leukemia, are plotted on a linear dose-response curve. The linear dose-response curve has no threshold; that is, there is no dose below which radiation is absolutely safe. The nonlinear/sigmoidal dose-response curve has a threshold and is thought to be generally correct for most somatic effects.
2120163. Which of the following statements regarding the human gonadal cells is (are) true?
21211. The female oogonia reproduce only during fetal life.
21222. The male spermatogonia reproduce continuously.
21233. Both male and female stem cells reproduce only during fetal life.
2124(A) 1 only
2125(B) 2 only
2126(C) 1 and 2 only
2127(D) 3 only
2128------------------------------ - (C) The development of male and female reproductive stem cells has important radiation protection implications. Male stem cells reproduce continuously. However, female stem cells develop only during fetal life; women are born with all the reproductive cells they will ever have. It is exceedingly important to shield children whenever possible because they have their reproductive futures ahead of them.
2129164. Protective devices such as lead aprons function to protect the user from
21301. scattered radiation
21312. the primary beam
21323. remnant radiation
2133(A) 1 only
2134(B) 1 and 2 only
2135(C) 1 and 3 only
2136(D) 1, 2, and 3
2137------------------------------ - (A) Protective apparel functions to protect the occupationally exposed person from scattered radiation only. Lead aprons and lead gloves do not protect from the primary beam. No one in the radiographic room except the patient must ever be exposed to the primary beam. The occupationally exposed and those (family and friends) who might assist a patient during an examination must wear protective apparel and keep out of the way of the primary beam.
2138165. The primary function of filtration is to reduce
2139(A) patient skin dose
2140(B) operator dose
2141(C) image noise
2142(D) scattered radiation
2143------------------------------ - (A) It is our ethical responsibility to minimize the radiation dose to our patients. X-rays produced at the tungsten target make up a heterogeneous primary beam. There are many "soft" (low-energy) photons that, if not removed by filters, would only contribute to greater patient skin dose. They are too weak to penetrate the patient and contribute to the image-forming radiation; they penetrate a small thickness of tissue and are absorbed.
2144166. Which of the following factors can affect the amount or the nature of radiation damage to biologic tissue?
21451. Radiation quality
21462. Absorbed dose
21473. Size of irradiated area
2148(A) 1 only
2149(B) 2 only
2150(C) 1 and 2 only
2151(D) 1, 2, and 3
2152------------------------------ - (D) Radiation quality determines degree of penetration and the amount of energy transferred to the irradiated tissue (LET). Certainly, the larger the absorbed radiation dose, the greater is the effect. Biologic effect is increased as the size of the irradiated area is increased. The nature of the effect is influenced by the location of irradiated tissue (bone marrow vs. gonads).
2153167. Examples of stochastic effects of radiation exposure include
21541. radiation-induced malignancy
21552. genetic effects
21563. leukemia
2157(A) 1 only
2158(B) 1 and 2 only
2159(C) 2 and 3 only
2160(D) 1, 2, and 3
2161------------------------------ - (D) Radiation effects that appear days or weeks following exposure (early effects) are in response to relatively high radiation doses. These should never occur in diagnostic radiology today; they occur only in response to doses much greater than those used in diagnostic radiology. One of the effects that may be noted in such a circumstance is the hematologic effect—reduced numbers of white blood cells, red blood cells, and platelets in the circulating blood. Immediate local tissue effects can include effects on the gonads (i.e., temporary infertility) and on the skin (e.g., epilation and erythema). Acute radiation lethality, or radiation death, occurs after an acute exposure and results in death in weeks or days. Radiation-induced malignancy, leukemia, and genetic effects are late effects (or stochastic effects) of radiation exposure. These can occur years after survival of an acute radiation dose or after exposure to low levels of radiation over a long period of time. Radiation workers need to be especially aware of the late effects of radiation because their exposure to radiation is usually low level over a long period of time. Occupational radiation protection guidelines, therefore, are based on late effects of radiation according to a linear, nonthreshold dose-response curve.
2162168. Which of the following tissues is (are) considered to be particularly radiosensitive?
21631. Intestinal mucous membrane
21642. Epidermis of extremities
21653. Optic nerves
2166(A) 1 only
2167(B) 1 and 2 only
2168(C) 2 and 3 only
2169(D) 1, 2, and 3
2170------------------------------ - (A) The most radiosensitive portion of the GI tract is the small bowel. Projecting from the lining of the small bowel are villi, from the crypts of Lieberkühn, which are responsible for the absorption of nutrients into the bloodstream. Because the cells of the villi are continually being cast off, new cells must continually arise from the crypts of Lieberkühn. Being highly mitotic, undifferentiated stem cells, they are very radiosensitive. Thus, the small bowel is the most radiosensitive portion of the GI tract. In the adult, the CNS is the most radioresistant system, and the epidermis is composed of radioresistant-mature, post-mitotic cells. (Dowd and Tilson, 2nd ed., p. 155)
2171169. Which of the following groups of exposure factors will deliver the least amount of exposure to the patient?
2172(A) 400 mA, 0.25 second, 100 kVp
2173(B) 600 mA, 0.33 second, 90 kVp
2174(C) 800 mA, 0.5 second, 80 kVp
2175(D) 800 mA, 1.0 second, 70 kVp
2176------------------------------ - 169. (A) The mAs setting regulates the quantity of radiation delivered to the patient, and the kVp setting regulates the quality (i.e., penetration) of the radiation delivered to the patient. Therefore, higher energy (i.e., more penetrating) radiation (which is more likely to exit the patient), accompanied by lower milliampere-seconds (mAs), is the safest combination for the patient.
2177170. Stochastic effects of radiation are those that
21781. have a threshold
21792. may be described as "all-or-nothing" effects
21803. are late effects
2181(A) 1 only
2182(B) 1 and 2 only
2183(C) 2 and 3 only
2184(D) 1, 2, and 3
2185------------------------------ - (C) Late effects of radiation can occur in cells that have survived a previous irradiation months or years earlier. These late effects, such as carcinogenesis and genetic effects, are "all-or-nothing" effects—either the organism develops cancer or it does not. Most late effects do not have a threshold dose; that is, any dose, however small, theoretically can induce an effect. Increasing that dose will increase the likelihood of the occurrence but will not affect its severity; these effects are termed stochastic. Nonstochastic effects are those that will not occur below a particular threshold dose and that increase in severity as the dose increases.
2186171. To within what percentage of the SID must the collimator light and actual irradiated area be accurate?
2187(A) 2%
2188(B) 5%
2189(C) 10%
2190(D) 15%
2191------------------------------ - (A) Restriction of field size is one important method of patient protection. However, the accuracy of the light field must be evaluated periodically as part of a quality assurance (QA) program. Guidelines for patient protection state that the collimator light and actual irradiated area must be accurate to within 2% of the SID.
2192172. Under what circumstances might a radiographer be required to wear two dosimeters?
21931. During pregnancy
21942. While performing vascular procedures
21953. While performing mobile radiography
2196(A) 1 and 2 only
2197(B) 2 only
2198(C) 2 and 3 only
2199(D) 1, 2, and 3
2200------------------------------ - (A) Radiographers usually are required to wear one dosimeter, positioned at their collar and worn outside a lead apron. Special circumstances, however, warrant the use of a second monitor. During pregnancy, a second "baby monitor" is worn at the abdomen, under any lead apron. During special vascular procedures, the dose to the radiographer can increase significantly. This is so because the leaded protective curtain is often absent from the fluorotower and because of the extensive use of cineradiography. As a result, the radiographer's upper extremities can receive a greater exposure (e.g., when assisting during catheter introduction), and a ring or bracelet badge is often recommended. A second dosimeter is not required when performing mobile radiography.
2201173. What quantity of radiation exposure to the reproductive organs is required to cause temporary infertility?
2202(A) 100 rad
2203(B) 200 rad
2204(C) 300 rad
2205(D) 400 rad
2206------------------------------ - (B) The reproductive cells are considered among the most radiosensitive cells in the body. The immature female sex cells are the oogonia; they mature to ova. The immature male sex cells are the spermatogonia; they mature to sperm. Different amounts of ionizing radiation to these cells can cause differing levels/degrees of response. Doses as low as 10 rad can cause menstrual changes in women and decrease the number of sperm in men. At 200 rad, temporary infertility is likely, and at 500 rad, sterility will result.
2207174. Which of the following personnel radiation monitors will provide an immediate reading?
2208(A) TLD
2209(B) Film badge
2210(C) Lithium fluoride chips
2211(D) Pocket dosimeter
2212------------------------------ - (D) A TLD is used to measure monthly exposure to radiation, as is the film badge. Lithium fluoride chips are the thermoluminescent material used in TLDs. A pocket dosimeter (a small personal ionization chamber) measures the quantity of ionizations occurring during the period worn and reads out in millirem; it is used primarily when working with large quantities of radiation.
2213175. The tabletop exposure rate during fluoroscopy shall not exceed
2214(A) 5 mR/min
2215(B) 10 R/min
2216(C) 10 mR/h
2217(D) 5 R/h
2218------------------------------ - (B) It is important to limit tabletop exposure during fluoroscopy because the SSD is so much less than in overhead radiography, so a much higher skin dose is delivered to the patient. For this reason, the tabletop exposure rate during fluoroscopy should not exceed 10 R/min.
2219177. If the exposure rate at 3 ft from the fluoroscopic table is 40 mR/h, what will be the exposure rate for 30 minutes at a distance of 5 ft from the table?
2220(A) 7 mR
2221(B) 12 mR
2222(C) 14 mR
2223(D) 24 mR
2224------------------------------ - (A) The intensity/exposure rate of radiation at a given distance from a point source is inversely proportional to the square of the distance.
2225178. Which of the following radiation protection measures is (are) appropriate for mobile radiography?
22261. The radiographer must be at least 6 ft from the patient and the x-ray tube during the exposure.
22272. The radiographer must announce in a loud voice that an exposure is about to be made and wait for personnel, visitors, and patients to temporarily leave the area.
22283. The radiographer must try to use the shortest practical SID.
2229(A) 1 and 2 only
2230(B) 1 and 3 only
2231(C) 2 and 3 only
2232(D) 1, 2, and 3
2233------------------------------ - (A) Mobile radiography (along with fluoroscopy and special procedures) is an area of higher occupational exposure. With no lead barrier to retreat behind, distance becomes the best source of protection. The exposure switch of mobile equipment must be manufactured to allow the technologist to stand at least 6 ft away from the patient and the x-ray tube. Hospital personnel, visitors, and patients also must be protected from unnecessary radiation exposure. Therefore, the radiographer must request that these people leave the immediate area until after the exposure is made and announce in a loud voice when the exposure is about to be made, allowing time for individuals to leave the area. The use of a short SID increases patient exposure and produces poor recorded detail.
2234179. Radiation that passes through the tube housing in directions other than that of the useful beam is termed
2235(A) scattered radiation
2236(B) secondary radiation
2237(C) leakage radiation
2238(D) remnant radiation
2239------------------------------ - (C) Scattered and secondary radiations are those that have deviated in direction while passing through a part. Leakage radiation is radiation that emerges from the leaded tube housing in directions other than that of the useful beam. Tube head construction must keep leakage radiation to less than 0.1 R/h at 1 m from the tube. Remnant radiation is the radiation that emerges from the patient to form the radiographic image.
2240180. The presence of ionizing radiation may be detected in which of the following ways?
22411. Ionizing effect on air
22422. Photographic effect on film emulsion
22433. Fluorescent effect on certain crystals
2244(A) 1 only
2245(B) 1 and 2 only
2246(C) 1 and 3 only
2247(D) 1, 2, and 3
2248------------------------------ - (D) The presence of ionizing radiation may be detected in several ways. It has an ionizing effect on air, which is the basic principle of the roentgen as unit of measurement. X-rays have a photographic effect on film emulsion, which is readily observable on radiographic images. The fluorescent effect on certain crystals, such as calcium tungstate and lanthanum, accounts for our use of these phosphors in intensifying screens. Radiation's physiologic effects have been demonstrated to be genetic damage, erythema, and cataractogenesis; many of these were noted by the early radiology pioneers.
2249181. Which of the following refers to a regular program of evaluation that ensures the proper functioning of x-ray equipment, thereby protecting both radiation workers and patients?
2250(A) Sensitometry
2251(B) Densitometry
2252(C) Quality assurance
2253(D) Modulation transfer function
2254------------------------------ - (C) Sensitometry and densitometry are used in evaluation of the film processor; they are just one portion of a complete QA program. Modulation transfer function (MTF) is used to express spatial resolution—another component of the QA program. A complete QA program includes testing of all components of the imaging system—processors, focal spot, x-ray timers, filters, intensifying screens, beam alignment, and so on.
2255182. What should be the radiographer's main objective regarding personal radiation safety?
2256(A) Not to exceed his or her dose limit
2257(B) To keep personal exposure as far below the dose limit as possible
2258(C) To avoid whole-body exposure
2259(D) To wear protective apparel when "holding" patients for exposures
2260------------------------------ - (B) Even the smallest exposure to radiation can be harmful. It, therefore, must be every radiographer's objective to keep his or her occupational exposure as far below the dose limit as possible. Radiology personnel never should hold patients during an x-ray examination.
2261184. If the exposure rate to a body standing 7 ft from a radiation source is 140 mR/h, what will be the dose to that body at a distance of 8 ft from the source in 30 minutes?
2262(A) 182.8 mR
2263(B) 107 mR
2264(C) 91.4 mR
2265(D) 53.6 mR
2266------------------------------ - (D) The relationship between x-ray intensity and distance from the source is expressed in the inverse-square law of radiation.
2267185. Which of the following types of radiation is (are) considered electromagnetic?
22681. X-ray
22692. Gamma
22703. Beta
2271(A) 1 only
2272(B) 1 and 2 only
2273(C) 2 and 3 only
2274(D) 1, 2, and 3
2275------------------------------ - (B) Alpha and beta radiation are particulate radiations; alpha is composed of two protons and two neutrons, and beta is identical to an electron. Gamma and x-radiation are electromagnetic, having wave-like fluctuations like other radiations of the electromagnetic spectrum (e.g., visible light and radio waves).
2276186. Which of the following features of fluoroscopic equipment is (are) designed especially to eliminate unnecessary radiation exposure to the patient and/or personnel?
22771. Bucky slot cover
22782. Exposure switch/foot pedal
22793. Cumulative exposure timer
2280(A) 1 only
2281(B) 1 and 2 only
2282(C) 2 and 3 only
2283(D) 1, 2, and 3
2284------------------------------ - (D) The Bucky slot cover shields the opening at the side of the table because the Bucky tray is parked at the end of the table for the fluoroscopy procedure; this is important because the opening created otherwise would allow scattered radiation to emerge at approximately the level of the operator's gonads. The exposure switch (usually a foot pedal) must be of the "dead man" type; that is, when the foot is released from the switch, there is immediate termination of exposure. The cumulative exposure timer sounds or interrupts the exposure after 5 minutes of fluoro time, thus making the fluoroscopist aware of accumulated fluoro time. In addition, source-to-tabletop distance is restricted to at least 15 in. for stationary equipment and at least 12 in. for mobile equipment. Increased source-to-tabletop distance increases source-to-patient distance, thereby decreasing patient dose.
2285187. Radiation output from a diagnostic x-ray tube is measured in which of the following units of measurement?
2286(A) Rad
2287(B) Rem
2288(C) Roentgen
2289(D) Becqueral
2290------------------------------ - (C) As x-ray photons emerge from the x-ray tube they immediately encounter air—before being intercepted by any material. The roentgen is the unit of exposure; it measures the quantity of ionizations in air. The roentgen is, therefore, the unit of choice for measuring x-ray tube output—and an ion-chamber dosimeter instrument is used for this purpose. Rad is an acronym for radiation absorbed dose; it measures the energy deposited in any material. Rem is an acronym for radiation-equivalent m an; it includes the relative biologic effectiveness. Becqueral is the SI unit of measurement for radioactivity.
2291188. Which of the following is (are) considered especially radiosensitive tissues?
22921. Bone marrow
22932. Intestinal crypt cells
22943. Erythroblasts
2295(A) 1 and 2 only
2296(B) 1 and 3 only
2297(C) 2 and 3 only
2298(D) 1, 2, and 3
2299------------------------------ - (D) All the tissues listed are considered especially radiosensitive. The intestinal crypt cells of Lieberkühn are responsible for the absorption of nutrients into the bloodstream. Because these cells are continually being cast off, new cells must continually arise. Being highly mitotic undifferentiated stem cells, they are very radiosensitive. Excessive radiation to the blood-forming organs (such as bone marrow) can cause leukemia or life-span shortening. Young, immature embryonic cells such as erythroblasts are listed among the most radiosensitive. Lymphocytes are the most radiosensitive cells in the body.
2300189. Which of the following safeguards is (are) taken to prevent inadvertent irradiation in early pregnancy?
23011. Patient postings
23022. Patient questionnaire
23033. Elective booking
2304(A) 1 and 2 only
2305(B) 1 and 3 only
2306(C) 2 and 3 only
2307(D) 1, 2, and 3
2308------------------------------ - (D) Elective booking of a radiologic examination after inquiring about the patient's previous menstrual cycle is the most effective means of preventing accidental exposure of a recently fertilized ovum. Patient questionnaires obtain this information from the patient and are also used often in an informed consent form. Patient postings in waiting and changing areas alert patients to advise the radiographer if there is any chance of pregnancy. These three safeguards replace the earlier 10-day rule, which is now obsolete.
2309190. The interaction between x-ray photons and tissue that is responsible for radiographic contrast but that also contributes significantly to patient dose is
2310(A) the photoelectric effect
2311(B) Compton scatter
2312(C) coherent scatter
2313(D) pair production
2314------------------------------ - (A) In the photoelectric effect, the incident (low-energy) photon is completely absorbed and thus is responsible for producing contrast and contributing to patient dose. The photoelectric effect is the interaction between x-ray and tissue that predominates in the diagnostic range. In Compton scatter, only partial absorption occurs, and most energy emerges as scattered photons. In coherent scatter, no energy is absorbed by the part; it all emerges as scattered photons. Pair production occurs only at very high energy levels, at least 1.02 MeV.
2315191. Which of the following is (are) acceptable way(s) to monitor the radiation exposure of those who are occupationally employed?
23161. TLD
23172. OSL dosimeter
23183. Quarterly blood cell count
2319(A) 1 only
2320(B) 1 and 2 only
2321(C) 1 and 3 only
2322(D) 1, 2, and 3
2323------------------------------ - (B) The OSL dosimeter and TLD are used frequently to measure the radiation exposure of radiographers. The pocket dosimeter may be employed by radiation workers who are exposed to higher doses of radiation and need a daily reading. A blood test is an unacceptable method of monitoring radiation dose effects because a very large dose would have to be received before blood changes would occur.
2324192. The genetic dose of radiation borne by each member of the reproductive population is called the
2325(A) genetically related dose
2326(B) genetically significant dose
2327(C) somatic related dose
2328(D) somatic significant dose
2329------------------------------ - (B) The genetically significant dose (GSD) illustrates that large exposures to a few people are cause for little concern when diluted by the total population. On the other hand, we all share the burden of that radiation received by the total population, especially as the use of medical radiation increases, so each individual's share of the total exposure increases.
2330193. According to the NCRP, the pregnant radiographer's gestational dose-equivalent limit for a 1-month period is
2331(A) 1 mSv
2332(B) 5 mSv
2333(C) 0.1 mSv
2334(D) 0.5 mSv
2335------------------------------ - (D) According to the NCRP, the annual occupational whole-body dose-equivalent limit is 50 mSv (5 rem or 5,000 mrem). The annual occupational whole-body dose-equivalent limit for students under the age of 18 years is 1 mSv (100 mrem or 0.1 rem). The annual occupational dose-equivalent limit for the lens of the eye is 150 mSv (15 rem). The annual occupational dose-equivalent limit for the thyroid, skin, and extremities is 500 mSv (50 rem). The total gestational dose-equivalent limit for the embryo/fetus of a pregnant radiographer is 5 mSv (500 mrem), not to exceed 0.5 mSv in 1 month.
2336194. Which of the following projections is most likely to deliver the largest dose to the ovaries?
2337(A) AP lumbar spine, 7 × 17 in. cassette, 80 kVp
2338(B) AP lumbar spine, 14 × 17 in. cassette, 80 kVp
2339(C) AP abdomen, 80 kVp
2340(D) AP abdomen, 70 kVp
2341------------------------------ - (B) Exposure dose to patients can be expressed as entrance skin exposure (ESE), sometimes referred to as skin entrance exposure (SEE). Exposure can also be expressed in terms of organ dose. Organ doses to the gonads, bone marrow, breast, thyroid, lens, and lung can be determined. Patient position and beam restriction often make a significant difference in patient dose. Examinations performed PA rather than AP often decrease exposure to sensitive organs. This is so because the lower energy x-ray photons will be absorbed by the anatomic structures closer to the x-ray source, and the higher energy photons will penetrate and exit the part (penetrating the sensitive part rather than being absorbed by it). PA abdomen radiographs deliver less quantity dose to the reproductive organs than AP abdomen radiographs do. An AP lumbar spine radiograph, 7 × 17 in. cassette, 80 kVp delivers about 74 mrad to the ovaries, whereas the same projection using a 14 × 17 in. cassette delivers 92 mrad. An AP abdomen radiograph with 70 kVp delivers 80 mrad, whereas at 80 kVp, the ovarian dose is 68 mrad.
2342195. The correct way(s) to check for cracks in lead aprons is (are)
23431. to fluoroscope them once a year
23442. to radiograph them at low kilovoltage twice a year
23453. by visual inspection
2346(A) 1 only
2347(B) 1 and 2 only
2348(C) 2 and 3 only
2349(D) 1, 2, and 3
2350------------------------------ - (A) Lead aprons require certain maintenance and care if they are to continue to provide protection from ionizing radiation. They can be kept clean with a damp cloth. It is very important that they be hung when not in use rather than being folded or left in a heap between examinations. A folded or crumpled position encourages the formation of cracks in the leaded vinyl. Lead aprons should be fluoro-scoped (at about 120 kVp) at least once a year to check for development of any cracks.
2351196. The target theory applies to
2352(A) spermatagonia
2353(B) oocytes
2354(C) lymphocytes
2355(D) DNA molecules
2356------------------------------ - (D) The principal interactions that occur between x-ray photons and body tissues in the diagnostic x-ray range, the photoelectric effect and Compton scatter, are ionization processes producing photoelectrons and recoil electrons that traverse tissue and subsequently ionize molecules. These interactions occur randomly but can lead to molecular damage in the form of impaired function or cell death. The target theory specifies that DNA molecules are the targets of greatest importance and sensitivity; that is, DNA is the key sensitive molecule. However, since the body is 65% to 80% water, most interactions between ionizing radiation and body cells will involve radiolysis of water rather than direct interaction with DNA. The two major types of effects that occur are the direct effect and the indirect effect. The direct effect usually occurs with high-LET radiations and when ionization occurs at the DNA molecule itself. The indirect effect, which occurs most frequently, happens when ionization takes place away from the DNA molecule in cellular water. However, the energy from the interaction can be transferred to the molecule via a free radical (formed by radiolysis of cellular water).
2357197. Which of the following is (are) features of fluoroscopic equipment designed especially to eliminate unnecessary radiation to patient and personnel?
23581. Protective curtain
23592. Filtration
23603. Collimation
2361(A) 1 only
2362(B) 1 and 2 only
2363(C) 1 and 3 only
2364(D) 1, 2, and 3
2365------------------------------ - (D) The protective curtain, which is usually made of leaded vinyl with at least 0.25 mm Pb equivalent, must be positioned between the patient and the fluoroscopist to greatly reduce the exposure of the fluoroscopist to energetic scatter from the patient. As with overhead equipment, fluoroscopic total filtration must be at least 2.5 mm Al equivalent to reduce excessive exposure to soft radiation. Collimator-beam alignment must be accurate to within 2%.
2366198. Which of the following has(have) been identified as source(s) of radon exposure?
23671. Indoors, in houses
23682. Smoking cigarettes
23693. Radiology departments
2370(A) 1 only
2371(B) 1 and 2 only
2372(C) 2 and 3 only
2373(D) 1, 2, and 3
2374------------------------------ - (B) Because minerals in rocks and the earth can emanate radioactivity, high levels of radon gas inside homes have been of recent concern. Another source of radon gas is from burning cigarettes, whether as a smoker or as passive exposure. Uranium miners have been identified with a much higher incidence of lung cancer; many of these individuals also were smokers. Radiology departments are not known as a source of radon gas exposure.
2375199. What is the relationship between LET and RBE?
2376(A) As LET increases, RBE increases.
2377(B) As LET increases, RBE decreases.
2378(C) As LET decreases, RBE increases.
2379(D) There is no direct relationship between LET and RBE.
2380------------------------------ - (A) LET increases with the ionizing potential of the radiation; for example, alpha particles are more ionizing than x-radiation; therefore, they have a higher LET. As ionizations and LET increase, there is greater possibility of an effect on living tissue; therefore, the RBE increases. The RBE (sometimes called the quality factor) of diagnostic x-rays is 1, the RBE of fast neutrons is 10, and the RBE of 5-MeV alpha particles is 20.
2381200. The biologic effect on an individual depends on which of the following?
23821. Type of tissue interaction(s)
23832. Amount of interactions
23843. Biologic differences
2385(A) 1 and 2 only
2386(B) 1 and 3 only
2387(C) 2 and 3 only
2388(D) 1, 2, and 3
2389------------------------------ - (D) Photoelectric interaction in tissue involves complete absorption of the incident photon, whereas Compton interactions involve only partial transfer of energy. The larger the quantity of radiation and the greater the number of photoelectric interactions, the greater is the patient dose. Radiation to more radiosensitive tissues such as gonadal tissue or blood-forming organs is more harmful than the same dose to muscle tissue.
2390
23911. Geometric blur can be evaluated using all the following devices except
2392(A) star pattern
2393(B) slit camera
2394(C) penetrometer
2395(D) pinhole camera
2396 --------------------------------- (C) Focal-spot size accuracy is related to the degree of geometric blur, that is, edge gradient or penumbra. Manufacturer tolerance for new focal spots is 50%; that is, a 0.3-mm focal spot actually may be 0.45 mm. Additionally, the focal spot can increase in size as the x-ray tube ages—hence the importance of testing newly arrived focal spots and periodic testing to monitor focal-spot changes. Focal-spot size can be measured with a pinhole camera, slit camera, or star-pattern-type resolution device. The pinhole camera is rather difficult to use accurately and requires the use of excessive tube (heat) loading. With a slit camera, two exposures are made; one measures the length of the focal spot, and the other measures the width. The star pattern, or similar resolution device such as the bar pattern, can measure focal-spot size as a function of geometric blur and is readily adaptable in a QA program to monitor focal-spot changes over a period of time. It is recommended that focal-spot size be checked on installation of a new x-ray tube and annually thereafter.
23972. What pixel size has a 512 × 512 matrix with a 20-cm field of view (FOV)?
2398(A) 0.07 mm/pixel
2399(B) 0.40 mm/pixel
2400(C) 0.04 mm/pixel
2401(D) 4.0 mm/pixel
2402 --------------------------------- (B) In digital imaging, pixel size is determined by dividing the field of view (FOV) by the matrix. In this case, the FOV is 20 cm; since the answer is expressed in millimeters, first change 20 cm to 200 mm. Then 200 divided by 512 equals 0.39 mm:
2403
2404
2405The FOV and matrix size are independent of one another; that is, either can be changed, and the other will remain unaffected. However, pixel size is affected by changes in either the FOV or matrix size. For example, if the matrix size is increased, pixel size decreases. If FOV is increased, pixel size increases. Pixel size is inversely related to resolution. As pixel size increases, resolution decreases.
24063. In electronic imaging, as digital image matrix size increases
24071. pixel size decreases
24082. resolution decreases
24093. pixel depth decreases
2410(A) 1 only
2411(B) 2 only
2412(C) 1 and 2 only
2413(D) 2 and 3 only
2414 --------------------------------- (A) Pixel depth is directly related to shades of gray—called dynamic range—and is measured in bits. The greater the number of bits, the more shades of gray. For example, a 1-bit (21) pixel will demonstrate 2 shades of gray, whereas a 6-bit (26) pixel can display 64 shades and a 7-bit (27) pixel 128 shades. However, pixel depth is unrelated to resolution.
2415A digital image is formed by a matrix of pixels (picture elements) in rows and columns. A matrix that has 512 pixels in each row and column is a 512 × 512 matrix. The term field of view is used to describe how much of the patient (e.g., 150-mm diameter) is included in the matrix. The matrix and the field of view can be changed independently without one affecting the other, but changes in either will change pixel size. As in traditional radiography, spatial resolution is measured in line pairs per millimeter (lp/mm). As matrix size is increased (e.g., from 512 × 512 to 1,024 × 1,024) there are more and smaller pixels in the matrix and, therefore, improved resolution. Fewer and larger pixels result in poor resolution, a "pixelly" image, that is, one in which you can actually see the individual pixel boxes.
2416An increase in added filtration will result in
24171. an increase in maximum energy of the x-ray beam
24182. a decrease in x-ray intensity
24193. an increase in effective energy of the x-ray beam
2420(A) 1 only
2421(B) 1 and 2 only
2422(C) 2 and 3 only
2423(D) 1, 2, and 3
2424 --------------------------------- (C) Added aluminum filtration removes more low-energy photons; therefore there is a decrease in the number of photons in the x-ray beam, that is, beam intensity. Because low-energy photons are removed, the overall average energy of the x-ray beam is increased. This process can also be referred to as beam hardening because its average energy is increased. The maximum energy of the beam is unchanged as long as the kV remains unchanged.
24256. SID affects recorded detail in which of the following ways?
2426(A) Recorded detail is directly related to SID.
2427(B) Recorded detail is inversely related to SID.
2428(C) As SID increases, recorded detail decreases.
2429(D) SID is not a detail factor.
2430 --------------------------------- (A) As the distance from focal spot to IR (SID) increases, so does recorded detail. Because the part is being exposed by more perpendicular (less divergent) rays, less magnification and blur are produced. Although the best recorded detail is obtained using a long SID, the necessary increase in exposure factors and resulting increased patient exposure become a problem. An optimal 40-in. SID is used for most radiography, with the major exception being chest examinations.
24317. Grid interspace material can be made of
24321. carbon fiber
24332. aluminum
24343. plastic fiber
2435(A) 1 only
2436(B) 1 and 2 only
2437(C) 2 and 3 only
2438(D) 1, 2, and 3
2439 --------------------------------- (C) Grids are composed of alternating strips of lead and radiolucent interspace material. The interspace material is either aluminum or plastic fiber. Aluminum resists moisture, is sturdier, provides a "smoother" appearance with less visible grid lines, but requires a higher mAs and therefore increases patient dose. Plastic fiber interspace material can be affected by moisture, resulting in warping. Carbon fiber is often used as image plate front material because of its durability and homogeneity.
24408. The exposure factors used for a particular nongrid x-ray image were 300 mA, 4 ms, and 90 kV. Another image, using an 8:1 grid, is requested. Which of the following groups of factors is most appropriate?
2441(A) 400 mA, 3 ms, 110 kV
2442(B) 400 mA, 12 ms, 90 kV
2443(C) 300 mA, 8 ms, 100 kV
2444(D) 200 mA, 240 ms, 90 kV
2445 --------------------------------- (B) The addition of a grid will help to clean up the scattered radiation produced by higher kilovoltage, but the grid requires an adjustment of milliampere-seconds. According to the grid conversion factors listed here, the addition of an 8:1 grid requires that the original milliampere-seconds be multiplied by a factor of 4:
2446
2447
2448The original milliampere-seconds value is 1.2. The ideal adjustment, therefore, requires a 4.8 mAs at 90 kV. Although 2.4 mAs with 100 kV (choice C), or 1.2 mAs with 110 kV (choice A), also might seem workable, an increase in kilovoltage would further compromise contrast, nullifying the effect of the grid. Additionally, kilovoltage exceeding 100 should not be used with an 8:1 grid.
244910. An increase in kilovoltage will have which of the following effects?
24501. More scattered radiation will be produced.
24512. The exposure rate will increase.
24523. Radiographic contrast will increase.
2453(A) 1 only
2454(B) 1 and 2 only
2455(C) 2 and 3 only
2456(D) 1, 2, and 3
2457 --------------------------------- (B) An increase in kilovoltage (photon energy) will result in a greater number (i.e., exposure rate) of scattered photons (Compton interaction). These scattered photons carry no useful information and contribute to radiation fog, thus decreasing radiographic contrast.
245811. The x-ray tube used in CT must be capable of
24591. high-speed rotation
24602. short pulsed exposures
24613. withstanding millions of heat units
2462(A) 1 only
2463(B) 1 and 2 only
2464(C) 2 and 3 only
2465(D) 1, 2, and 3
2466 --------------------------------- (D) A CT imaging system has three component parts—a gantry, a computer, and an operating console. The gantry component includes an x-ray tube, a detector array, a high-voltage generator, a collimator assembly, and a patient couch with its motorized mechanism. Although the CT x-ray tube is similar to direct-projection x-ray tubes, it has several special requirements. The CT x-ray tube must have a very high short-exposure rating and must be capable of tolerating several million heat units while still having a small focal spot for optimal resolution. To help tolerate the very high production of heat units, the anode must be capable of high-speed rotation. The x-ray tube produces a pulsed x-ray beam (1-5 ms) using up to about 1,000 mA.
246713. Decreasing field size from 14 × 17 in. to 8 × 10 in., with no other changes, will
2468(A) decrease the amount of scattered radiation generated within the part
2469(B) increase the amount of scattered radiation generated within the part
2470(C) increase x-ray penetration of the part
2471(D) decrease x-ray penetration of the part
2472 --------------------------------- (A) Limiting the size of the radiographic field (irradiated area) serves to limit the amount of scattered radiation produced within the anatomic part. Therefore, as field size decreases, scattered radiation production decreases, and image quality increases. Limiting the size of the radiographic field is a very effective means of reducing the quantity of non-information-carrying scattered radiation (fog) produced, resulting in improved detail visibility. Limiting the size of the radiographic field is also the most effective means of patient radiation protection.
247314. Which of the following groups of exposure factors will produce the most radiographic density?
2474(A) 100 mA, 50 ms
2475(B) 200 mA, 40 ms
2476(C) 400 mA, 70 ms
2477(D) 600 mA, 30 ms
2478 --------------------------------- (C) Milliampere-seconds (mAs) is the exposure factor that is used to regulate radiographic density. Using the equation milliamperage × time = mAs, determine each mAs: , , , . Group C will produce the most radiographic density.
247915. The component of a CR image plate (IP) that records the radiologic image is the
2480(A) emulsion
2481(B) helium-neon laser
2482(C) photostimulable phosphor
2483(D) scanner-reader
2484 --------------------------------- (C) Inside the IP is the photostimulable phosphor (PSP). This PSP (or SPS—Storage Phosphor Screen), with its layer of europium-activated barium fluorohalide, serves as the IR because it is exposed in the traditional manner and receives the latent image. The PSP can store the latent image for several hours; after about 8 hours, noticeable image fading will occur. Once the IP is placed into the CR processor (scanner or reader), the PSP plate is removed automatically. The latent image on the PSP is changed to a manifest image as it is scanned by a narrow, high-intensity helium-neon laser to obtain the pixel data. As the PSP is scanned in the reader, it releases a violet light—a process referred to as photostimulated luminescence (PSL).
248516. An x-ray image of the ankle was made at 40-SID, 200 mA, 50 ms, 70 kV, 0.6 mm focal spot, and minimal OID. Which of the following modifications would result in the greatest increase in magnification?
2486(A) 1.2 mm focal spot
2487(B) 36-in. SID
2488(C) 44-in. SID
2489(D) 4-in. OID
2490 --------------------------------- (D) All the factor changes affect recorded detail, but focal spot size does not affect magnification. An increase in SID would decrease magnification. Although a decrease in SID will increase magnification, it does not have as significant an effect as an increase in OID. In general, it requires an increase of 7 in. SID to compensate for every inch of OID.
249117. A lateral radiograph of the cervical spine was made at 40 in. using 300 mA and 0.03 second exposure. If it is desired to increase the distance to 72 in., what should be the new milliampere (mA) setting, all other factors remaining constant?
2492(A) 400
2493(B) 800
2494(C) 1,000
2495(D) 1,200
2496 --------------------------------- (C) When exposure rate decreases (as a result of increased SID), an appropriate increase in milliampere-seconds is required to maintain the original radiographic density. Unless exposure is increased, the resulting radiograph will be underexposed. The formula used to determine the new milliampere-seconds value (density-maintenance formula) is substituting known values:
2497
2498
2499Substituting known values:
2500
2501
2502Thus, mAs at 72 in. SID. To determine the required milliamperes ,
250318. Which of the following statements regarding dual x-ray absorptiometry is (are) true?
25041. Radiation dose is low.
25052. Only low-energy photons are used.
25063. Photon attenuation by bone is calculated.
2507(A) 1 only
2508(B) 1 and 2 only
2509(C) 1 and 3 only
2510(D) 1, 2, and 3
2511 --------------------------------- (C) Dual x-ray absorptiometry (DXA) imaging is used to evaluate bone mineral density (BMD). It is the most widely used method of bone densitometry—it is low-dose, precise, and uncomplicated to use/perform. DXA uses two photon energies—one for soft tissue and one for bone. Since bone is denser and attenuates x-ray photons more readily, photon attenuation is calculated to represent the degree of bone density. Bone densitometry DXA can be used to evaluate bone mineral content of the body, or part of it, to diagnose osteoporosis or to evaluate the effectiveness of treatments for osteoporosis.
251219. The luminescent light emitted by the PSP is transformed into the image seen on the CRT by the
2513(A) PSP
2514(B) scanner-reader
2515(C) ADC
2516(D) helium-neon laser
2517 --------------------------------- (C) The exposed IP is placed into the CR scanner/reader, where the PSP/SPS is removed automatically. The latent image appears as the PSP is scanned by a narrow, high-intensity helium-neon laser to obtain the pixel data. As the PSP plate is scanned in the CR reader, it releases a violet light—a process referred to as photostimulated luminescence (PSL). The luminescent light is converted to electrical energy representing the analog image. The electrical energy is sent to an analog-to-digital converter (ADC), where it is digitized and becomes the digital image that is displayed eventually (after a short delay) on a high-resolution monitor and/or printed out by a laser printer. The digitized images can also be manipulated in postprocessing, transmitted electronically, and stored/archived.
251821. Which of the following is/are true when comparing film-screen imaging to CR imaging?
25191. CR DQE is better than film-screen DQE.
25202. CR has a wider exposure range than film-screen.
25213. CR has better spatial resolution than film-screen.
2522(A) 1 only
2523(B) 1 and 2 only
2524(C) 2 and 3 only
2525(D) 1, 2, and 3
2526 --------------------------------- (B) CR systems convert x-ray photons into useful information much more efficiently than film-screen systems, hence a far better DQE. CR also converts that information over a far wider exposure range (about 104 times wider) than screen film. The single negative aspect of CR is its limited spatial resolution (image detail). While film-screen systems resolve about 10-15 lp/mm, CR resolution is about 3-5 lp/mm.
252722. The term windowing describes the practice of
2528(A) varying the automatic brightness control
2529(B) changing the image brightness and/or contrast scale
2530(C) varying the FOV
2531(D) increasing resolution
2532 --------------------------------- (B) In electronic imaging (CR/DR), the radiographer can manipulate the digital image displayed on the CRT through postprocessing. One way to alter image contrast and/or brightness is through windowing. This refers to some change made to window width and/or window level. Change in window width changes the number of gray shades, that is, contrast scale/contrast resolution. Change in window level changes the image brightness. Windowing and other postprocessing mechanisms permit the radiographer to produce "special effects" such as edge enhancement, image stitching, and image inversion, rotation, and reversal. A digital image is formed by a matrix of pixels in rows and columns. A matrix having 512 pixels in each row and column is a 512 × 512 matrix. The term field of view is used to describe how much of the patient (e.g., 150-mm diameter) is included in the matrix. The matrix or field of view can be changed without affecting the other, but changes in either will change pixel size. Automatic brightness control is associated with image intensification.
253323. Foreshortening can be caused by
2534(A) the radiographic object being placed at an angle to the IR
2535(B) excessive distance between the object and the IR
2536(C) insufficient distance between the focus and the IR
2537(D) excessive distance between the focus and the IR
2538 --------------------------------- (A) Aligning the x-ray tube, anatomic part, and IR so that they are parallel reduces shape distortion. Angulation of the long axis of the part with respect to the IR results in foreshortening of the object. Tube angulation causes elongation of the part. Size distortion (magnification) is inversely proportional to SID and directly proportional to OID. Decreasing the SID and increasing the OID serve to increase size distortion.
253924. Acceptable method(s) of minimizing motion unsharpness is (are)
25401. suspended respiration
25412. short exposure time
25423. patient instruction
2543(A) 1 only
2544(B) 1 and 2 only
2545(C) 1 and 3 only
2546(D) 1, 2, and 3
2547 --------------------------------- (D) The shortest possible exposure time should be used to minimize motion unsharpness. Motion causes unsharpness that destroys detail. Careful and accurate patient instruction is essential for minimizing voluntary motion. Suspended respiration eliminates respiratory motion. Using the shortest possible exposure time is essential for decreasing involuntary motion. Immobilization is also very useful in eliminating motion unsharpness.
254825. Using fixed milliampere-seconds and variable kilovoltage technical factors, each centimeter increase in patient thickness requires what adjustment in kilovoltage?
2549(A) Increase 2 kV
2550(B) Decrease 2 kV
2551(C) Increase 4 kV
2552(D) Decrease 4 kV
2553 --------------------------------- (A) When the variable-kilovoltage method is used, a particular milliampere-seconds value is assigned to each body part. As part thickness increases, the kilovoltage (i.e., penetration) is also increased. The body part being radiographed must be measured carefully, and for each centimeter of increase in thickness, 2 kV is added to the exposure.
255426. Unopened boxes of radiographic film should be stored away from radiation and
2555(A) in the horizontal position
2556(B) in the vertical position
2557(C) stacked with the oldest on top
2558(D) stacked with the newest on top
2559 --------------------------------- (B) Boxes of x-ray film, especially the larger sizes, should be stored in the vertical (upright) position. If film boxes are stacked on one another, the sensitive emulsion can be affected by pressure from the boxes above. Pressure marks are produced and result in loss of contrast in that area of the radiographic image. When retrieving x-ray film from storage, the oldest should be used first.
256027. If a duration of 0.05 second was selected for a particular exposure, what milliamperage would be necessary to produce 30 mAs?
2561(A) 900
2562(B) 600
2563(C) 500
2564(D) 300
2565 --------------------------------- (B) The formula for mAs is . Substituting known values:
256628. Factors that contribute to film fog include
25671. the age of the film
25682. excessive exposure to safelight
25693. processor chemistry
2570(A) 1 only
2571(B) 1 and 2 only
2572(C) 1 and 3 only
2573(D) 1, 2, and 3
2574 --------------------------------- (D) Film age is an important consideration when determining the causes of film fog. Outdated film will exhibit loss of contrast in the form of fog and loss of speed. A safelight is "safe" only for practical periods of time required for the necessary handling of film. Films that are left out on the darkroom counter can be fogged by excessive exposure to the safelight. Film emulsion is much more sensitive to safelight fog after exposure. The high temperatures required for automatic processors' rapid processing are a source of film fog. Daily QA ensures that fog levels do not exceed the upper limit of 0.2 density.
257529. X-ray photon energy is inversely related to
25761. photon wavelength
25772. applied milliamperes (mA)
25783. applied kilovoltage (kV)
2579(A) 1 only
2580(B) 1 and 2 only
2581(C) 1 and 3 only
2582(D) 1, 2, and 3
2583 --------------------------------- (A) As kilovoltage is increased, more high-energy photons are produced, and the overall energy of the primary beam is increased. Photon energy is inversely related to wavelength; that is, as photon energy increases, wavelength decreases. An increase in milliamperage serves to increase the number of photons produced at the target but is unrelated to their energy.
258431. Characteristics of DR imaging include
25851. solid-state detector receptor plates
25862. a direct-capture imaging system
25873. immediate image display
2588(A) 1 only
2589(B) 1 and 3 only
2590(C) 2 and 3 only
2591(D) 1, 2, and 3
2592 --------------------------------- (D) Whereas CR uses traditional x-ray devices to enclose and protect the PSP/SPS, digital radiography (DR) requires the use of somewhat different equipment. DR does not use cassettes or a traditional x-ray table; it is a direct-capture system of x-ray imaging. DR uses solid-state detector plates as the x-ray IR (instead of a cassette in the Bucky tray) to intercept the collimated x-ray beam and form the latent image. The solid-state detector plates are made of barium fluorohalide compounds similar to that used in CR's PSP/SPSs. DR affords the advantage of immediate display of the image, compared with CR's delayed image display.
259332. Compared with a low-ratio grid, a high-ratio grid will
25941. allow more centering latitude
25952. absorb more scattered radiation
25963. absorb more primary radiation
2597(A) 1 only
2598(B) 1 and 2 only
2599(C) 2 and 3 only
2600(D) 1, 2, and 3
2601 --------------------------------- (C) Grid ratio is defined as the height of the lead strips to the width of the interspace material (Figure 4-32). The higher the lead strips (or the smaller the distance between the strips), the higher the grid ratio, and the greater the percentage of scattered radiation absorbed. However, a grid does absorb some primary/useful radiation as well. The higher the lead strips, the more critical is the need for accurate centering because the lead strips will more readily trap photons whose direction does not parallel them.
260233. Subject/object unsharpness can result from all of the following except when
2603(A) object shape does not coincide with the shape of x-ray beam
2604(B) object plane is not parallel with x-ray tube and/or IR
2605(C) anatomic object(s) of interest is/are in the path of the CR
2606(D) anatomic object(s) of interest is/are a distance from the IR
2607 --------------------------------- (C) A certain amount of object unsharpness is an inherent part of every radiographic image because of the position and shape of anatomic structures within the body. Structures within the three-dimensional human body lie in different planes. Additionally, the three-dimensional shape of solid anatomic structures rarely coincides with the shape of the divergent beam. Consequently, some structures are imaged with more inherent distortion than others, and shapes of anatomic structures can be entirely misrepresented. Structures farther from the IR will be distorted (i.e., magnified) more than those closer to the IR; structures closer to the x-ray source will be distorted (i.e., magnified) more than those farther from the x-ray source.
2608For the shape of anatomic structures to be accurately recorded, the structures must be parallel to the x-ray tube and the IR, and aligned with the central ray (CR). The shape of anatomic structures lying at an angle within the body or placed away from the CR will be misrepresented on the IR. There are two types of shape distortion. If a linear structure is angled within the body, that is, not parallel with the long axis of the part/body and not parallel to the IR, that anatomic structure will appear smaller—it will be foreshortened. On the other hand, elongation occurs when the x-ray tube is angled.
2609Image details placed away from the path of the CR will be exposed by more divergent rays, resulting in rotation distortion. This is why the CR must be directed to the part of greatest interest.
2610Unless the edges of a three-dimensional object conform to the shape of the x-ray beam, blur or unsharpness will occur at the partially attenuating edge of the object. This can be accompanied by changes in radiographic/image density, according to the thickness of areas traversed by the x-ray beam.
261135. To be suitable for use in an image intensifier's input screen, a phosphor should have which of the following characteristics?
26121. High conversion efficiency
26132. High x-ray absorption
26143. High atomic number
2615(A) 1 only
2616(B) 3 only
2617(C) 1 and 2 only
2618(D) 1, 2, and 3
2619 --------------------------------- (D) Phosphors that have a high atomic number are more likely to absorb a high percentage of the incident x-ray photons and convert x-ray photon energy to fluorescent light energy. How efficiently the phosphors detect and interact with the x-ray photons is termed quantum detection efficiency. How effectively the phosphors make this energy conversion is termed conversion efficiency.
262036. Resolution in CR increases as
26211. laser beam size decreases
26222. monitor matrix size decreases
26233. PSP crystal size decreases
2624(A) 1 only
2625(B) 1 and 2 only
2626(C) 1 and 3 only
2627(D) 1, 2, and 3
2628 --------------------------------- (C) Spatial resolution in CR is impacted by the size of the PSP, the size of the scanning laser beam, and monitor matrix size. High-resolution monitors (2-4 MP, megapixels) are required for high-quality, high-resolution image display. The larger the matrix size, the better is the image resolution. Typical image matrix size (rows and columns) used in chest radiography is 2,048 × 2,048. As in traditional radiography, spatial resolution is measured in line pairs per millimeter. As matrix size is increased, there are more and smaller pixels in the matrix and, therefore, improved spatial resolution. Other factors contributing to image resolution are the size of the laser beam and the size of the PSP/SPS phosphors. Smaller phosphor size improves resolution in ways similar to that of intensifying screens—anything that causes an increase in light diffusion will result in a decrease in resolution. Smaller phosphors in the PSP (SPS) plate allow less light diffusion. Additionally, the scanning laser light must be of the correct intensity and size. A narrow laser beam is required for optimal resolution.
262937. Pathologic or abnormal conditions that would require an increase in exposure factors include all of the following except
2630(A) atelectasis
2631(B) pneumoperitoneum
2632(C) Paget disease
2633(D) congestive heart failure
2634 --------------------------------- (B) Pathologic processes and abnormal conditions that alter tissue composition or thickness can have a significant effect on image density. The radiographer must be aware of these variants and processes to make an appropriate and accurate adjustment of technical factors.
2635Examples of additive pathologic conditions:
2636 
2637• Ascites
2638• Rheumatoid arthritis
2639• Paget disease
2640• Pneumonia
2641• Atelectasis
2642• Congestive heart failure
2643• Edematous tissue
2644Examples of destructive pathologic conditions:
2645 
2646• Osteoporosis
2647• Osteomalacia
2648• Pneumoperitoneum
2649• Emphysema
2650• Degenerative arthritis
2651• Atrophic and necrotic conditions
265238. In radiography of a large abdomen, which of the following is (are) effective way(s) to minimize the amount of scattered radiation reaching the image receptor (IR)?
26531. Use of close collimation
26542. Use of low mAs
26553. Use of a low-ratio grid
2656(A) 1 only
2657(B) 1 and 2 only
2658(C) 1 and 3 only
2659(D) 1, 2, and 3
2660 --------------------------------- (A) One way to minimize scattered radiation reaching the IR is to use optimal kilovoltage; excessive kilovoltage increases the production of scattered radiation. Close collimation is exceedingly important because the smaller the volume of irradiated material, the less scattered radiation will be produced. The mAs selection has no impact on scattered radiation production or cleanup. Low-ratio grids allow a greater percentage of scattered radiation to reach the IR. Use of a high-ratio grid will clean up a greater amount of scattered radiation before it reaches the IR. Use of a compression band, or the prone position, in a large abdomen has the effect of making the abdomen "thinner"; it will, therefore, generate less scattered radiation.
266139. Which of the following factors contribute(s) to the efficient performance of a grid?
26621. Grid ratio
26632. Number of lead strips per inch
26643. Amount of scatter transmitted through the grid
2665(A) 1 only
2666(B) 2 only
2667(C) 1 and 2 only
2668(D) 1, 2, and 3
2669 --------------------------------- (D) Grid ratio is defined as the ratio of the height of the lead strips to the width of the interspace material; the higher the lead strips, the more scattered radiation they will trap and the greater is the grid's efficiency. The greater the number of lead strips per inch, the thinner and less visible they will be on the finished radiograph. The function of a grid is to absorb scattered radiation in order to improve radiographic contrast. The selectivity of a grid is determined by the amount of primary radiation transmitted through the grid divided by the amount of scattered radiation transmitted through the grid.
267041. All the following affect the exposure rate of the primary beam except
2671(A) milliamperage
2672(B) kilovoltage
2673(C) distance
2674(D) field size
2675 --------------------------------- (D) Exposure rate is regulated by milliamperage. Distance significantly affects the exposure rate according to the inverse-square law of radiation. Kilovoltage also has an effect on exposure rate because an increase in kilovoltage will increase the number of high-energy photons produced at the target. The size of the x-ray field determines the volume of tissue irradiated, and hence the amount of scattered radiation generated, but is unrelated to the exposure rate.
267642. Factors that determine the production of scattered radiation include
26771. field size
26782. beam restriction
26793. kilovoltage
2680(A) 1 only
2681(B) 1 and 2 only
2682(C) 2 and 3 only
2683(D) 1, 2, and 3
2684 --------------------------------- (D) High kV may be desirable in terms of patient dose, tube life, and making more details visible, but use of excessively high kV will result in production of excessive amounts of scattered radiation and fog, resulting in diminished visibility of image details. Much of the scattered radiation produced is highly energetic and exits the patient along with useful image-forming radiation. Scattered radiation carries no useful information but adds noise in the form of fog, thereby impairing detail visibility.
2685Because scattered radiation can have such a devastating effect on image contrast, it is essential that radiographers are knowledgeable about methods of reducing its production. The three factors that have a significant effect on the production of scattered radiation are beam restriction (i.e., size of irradiated field), kV, and thickness/volume and density of tissues.
2686Perhaps the most important way to limit the production of scattered radiation and improve contrast is by limiting the size of the irradiated field, that is, through beam restriction. As the size of the x-ray field is reduced, there is less area and tissue volume for scattered radiation to be generated.
2687As the volume and/or density of the irradiated tissues increase(s), so does scattered radiation. Thicker and denser anatomic structures will generate more scattered radiation. Compression of certain parts can occasionally be used to minimize the effect of scatter, but close collimation can always be used effectively.
268843. Image contrast is a result of
26891. differential tissue absorption
26902. atomic number of tissue being traversed
26913. proper regulation of milliampere-seconds
2692(A) 1 only
2693(B) 1 and 2 only
2694(C) 1 and 3 only
2695(D) 1, 2, and 3
2696 --------------------------------- (B) Radiographic contrast is defined as the degree of difference between adjacent densities. These density differences represent sometimes very subtle differences in the absorbing properties of adjacent body tissues. The radiographic subject, the patient, is composed of many different tissue types that have varying densities, resulting in varying degrees of photon attenuation and absorption. The atomic number of the tissues under investigation is directly related to their attenuation coefficient. This differential absorption contributes to the various shades of gray (scale of radiographic contrast) on the finished radiograph. Normal tissue density may be altered significantly in the presence of pathologic processes. The technical factor used to regulate contrast is kilovoltage. Radiographic contrast is unrelated to milliampere-seconds.
269745. A 5-in. object to be radiographed at a 44-in. SID lies 6 in. from the IR. What will be the image width?
2698(A) 5.1 in.
2699(B) 5.7 in.
2700(C) 6.1 in.
2701(D) 6.7 in.
2702 --------------------------------- (B) Magnification is part of every radiographic image. Anatomic parts within the body are at various distances from the IR and, therefore, have various degrees of magnification. The formula used to determine the amount of image magnification is
2703
2704
2705Substituting known values:
2706
2707
2708Thus, . image width.
270946. In comparison with 60 kV, 80 kV will
27101. permit greater exposure latitude
27112. produce more scattered radiation
27123. produce shorter-scale contrast
2713(A) 1 only
2714(B) 2 only
2715(C) 1 and 2 only
2716(D) 2 and 3 only
2717 --------------------------------- (C) The higher the kilovoltage range, the greater is the exposure latitude (margin of error in exposure). Higher kilovoltage produces more energetic photons, is more penetrating, and produces more grays on the radiographic image, lengthening the scale of contrast. As kilovoltage increases, the percentage of scattered radiation also increases.
271847. The term pixel is associated with all of the following except
2719(A) two dimensional
2720(B) picture element
2721(C) measured in xy direction
2722(D) how much of the part is included in the matrix
2723 --------------------------------- (D) Digital image storage is located in a pixel, which is a two-dimensional "picture element," measured in the "XY" direction. The third dimension, "Z" direction, in the matrix of pixels is the depth that is referred to as the voxel (volume element). The depth of the block is the number of bits required to describe the gray level that each pixel can take on—known as the bit depth.
2724Bit depth in CT is approximately 212 with a dynamic range of almost 5,000 gray shades, approximately 214 in CR/DR with a dynamic range of more than 16,000 gray shades, and approximately 216 in digital mammography with a dynamic range of more than 65,500 gray shades. The matrix is the number of pixels in the XY direction. As matrix size increases, for a fixed FOV, pixel size is smaller and better spatial resolution results. An electronic/digital image is formed by a matrix of pixels in rows and columns. A matrix having 512 pixels in each row and column is a 512 × 512 matrix (a typical CT image).
2725The term FOV is used to describe how much of the patient is included in the matrix. Either the matrix or the FOV can be changed without one affecting the other, but changes in either will change pixel size. As FOV increases, for a fixed matrix size, the size of each pixel increases and spatial resolution decreases. Fewer and larger pixels result in a poor-resolution "pixelly" or "mosaicked" image, that is, one in which you can actually see the individual pixel boxes.
272648. Misalignment of the tube-part-IR relationship results in
2727(A) shape distortion
2728(B) size distortion
2729(C) magnification
2730(D) blur
2731 --------------------------------- (A) Shape distortion (e.g., foreshortening or elongation) is caused by improper alignment of the tube, part, and IR. Size distortion, or magnification, is caused by too great an OID or too short an SID. Focal-spot blur is caused by the use of a large focal spot.
273249. Causes of grid cutoff, when using focused reciprocating grids, include the following?
27331. Inadequate SID
27342. X-ray tube off-center with the long axis of the lead strips
27353. Angling the beam in the direction of the lead strips
2736(A) 1 only
2737(B) 1 and 2 only
2738(C) 2 and 3 only
2739(D) 1, 2, and 3
2740 --------------------------------- (A) If the SID is above or below the recommended focusing distance, the primary beam will not coincide with the angled lead strips at their lateral edges. Consequently, there will be absorption of the primary beam termed grid cutoff. If the central ray is off-center longitudinally, there will be no ill effects. If the central ray is off-center side to side, the lead strips are no longer parallel with the divergent x-ray beam, and there will be loss of density owing to grid cutoff. Central ray angulation in the direction of the lead strips is appropriate and will not cause grid cutoff. Central ray angulation against the direction of the lead strips will cause grid cutoff.
274151. Using a short (25-30 in.) SID with a large (14 × 17 in.) IR is likely to
2742(A) increase the scale of contrast
2743(B) increase the anode heel effect
2744(C) cause malfunction of the AEC
2745(D) cause premature termination of the exposure
2746 --------------------------------- (B) Use of a short SID with a large-size IR (and also with anode angles of 10 degrees or less) causes the anode heel effect to be much more apparent. The x-ray beam needs to diverge more to cover a large-size IR, and it needs to diverge even more for coverage as the SID decreases. The x-ray beam has no problem diverging toward the cathode end of the beam, but as it tries to diverge toward the anode end of the beam, it is eventually stopped by the anode (x-ray photons are absorbed by the anode). This causes a decrease in beam intensity at the anode end of the beam and is characteristic of the anode heel effect.
274752. Which of the following groups of factors would produce the least radiographic density?
2748(A) 400 mA, 0.010 second, 94 kV, 100-speed screens
2749(B) 500 mA, 0.008 second, 94 kV, 200-speed screens
2750(C) 200 mA, 0.040 second, 94 kV, 50-speed screens
2751(D) 100 mA, 0.020 second, 80 kV, 200-speed screens
2752 --------------------------------- (D) Each milliampere-second setting is determined [; ; ; ] and numbered in order of greatest to least density [; (A) and ; ]. Then, the kilovoltages are reviewed and also numbered in order of greatest to least density [(A), (B), and ; ]. Next, screen speeds are numbered from greatest density-producing to least density-producing [(D) and ; ; ]. Finally, the numbers assigned to the milliampere-seconds, kilovoltage, and screen speed are added up for each of the four groups [; (A) and ; ]; the lowest total (B) indicates the group of factors that will produce the greatest radiographic density; the highest total (D) indicates the group of factors that will produce the least radiographic density. This process is illustrated as follows:
275353. Chemical fog may be attributed to
27541. excessive developer temperature
27552. oxidized developer
27563. excessive replenishment
2757(A) 1 only
2758(B) 1 and 2 only
2759(C) 2 and 3 only
2760(D) 1, 2, and 3
2761 --------------------------------- (D) If developer temperature is too high, some of the less exposed or unexposed silver halide crystals may be reduced, thus creating chemical fog. If the developer solution has become oxidized from exposure to air, chemical fog also results. If developer replenishment is excessive, and too much new solution is replacing the deteriorated developer, chemical fog is again the result.
276254. Greater latitude is available to the radiographer in which of the following circumstances?
27631. Using high-kV technical factors
27642. Using a low-ratio grid
27653. Using low-kV technical factors
2766(A) 1 only
2767(B) 1 and 2 only
2768(C) 2 and 3 only
2769(D) 3 only
2770 --------------------------------- (B) In the low-kilovoltage ranges, a difference of just a few kilovolts makes a very noticeable radiographic difference, therefore offering little margin for error/latitude. High-kilovolt technical factors offer much greater margin for error; in the high-kV ranges, an error of a few kV makes little/no difference in the resulting image. Lower-ratio grids offer more tube-centering latitude than high-ratio grids.
277155. The differences between CR and DR include
27721. CR uses IPs.
27732. CR has higher DQE and lower patient dose.
27743. CR images are displayed immediately.
2775(A) 1 only
2776(B) 1 and 2 only
2777(C) 2 and 3 only
2778(D) 1, 2, and 3
2779 --------------------------------- (A) While CR utilizes traditional x-ray tables and IPs to enclose and protect the flexible PSP screen, DR requires the use of significantly different equipment. DR does not use IPs or a traditional x-ray table—it is a direct-capture/conversion, or indirect capture/conversion, system of x-ray imaging. Besides eliminating IPs and their handling, DR affords the advantage of immediate display of the image (compared with CR's slightly delayed image display), and DR exposures can be lower because of the detector's higher DQE (i.e., ability to perceive and interact with x-ray photons). DR, like CR, also offers the advantage of image preview and postprocessing.
278056. The term voxel is associated with all of the following except
2781(A) bit depth
2782(B) volume element
2783(C) measured in Z direction
2784(D) field of view
2785 --------------------------------- (D) Digital image storage is located in a pixel, which is a two-dimensional "picture element," measured in the "XY" direction. The third dimension, "Z" direction, in the matrix of pixels is the depth that is referred to as the voxel (volume element). The depth of the block is the number of bits required to describe the gray level that each pixel can take on—known as the bit depth.
2786Bit depth in CT is approximately 212 with a dynamic range of almost 5,000 gray shades, approximately 214 in CR/DR with a dynamic range of more than 16,000 gray shades, and approximately 216 in digital mammography with a dynamic range of more than 65,500 gray shades. The matrix is the number of pixels in the XY direction. As matrix size increases, for a fixed FOV, pixel size is smaller and better spatial resolution results. An electronic/digital image is formed by a matrix of pixels in rows and columns. A matrix having 512 pixels in each row and column is a 512 × 512 matrix (a typical CT image).
2787The term FOV is used to describe how much of the patient is included in the matrix. Either the matrix or the FOV can be changed without one affecting the other, but changes in either will change pixel size. As FOV increases, for a fixed matrix size, the size of each pixel increases and spatial resolution decreases. Fewer and larger pixels result in a poor-resolution "pixelly" or "mosaicked" image, that is, one in which you can actually see the individual pixel boxes.
278857. Using a 48-in. SID, how much OID must be introduced to magnify an object two times?
2789(A) 8-in. OID
2790(B) 12-in. OID
2791(C) 16-in. OID
2792(D) 24-in. OID
2793 --------------------------------- (D) Magnification radiography may be used to delineate a suspected hairline fracture or to enlarge tiny, contrast-filled blood vessels. It also has application in mammography. To magnify an object to twice its actual size, the part must be placed midway between the focal spot and the IR.
279458. A particular radiograph was produced using 12 mAs and 85 kV with a 16:1 ratio grid. The radiograph is to be repeated using an 8:1 ratio grid. What should be the new milliampere-seconds value?
2795(A) 3
2796(B) 6
2797(C) 8
2798(D) 10
2799 --------------------------------- (C) To change nongrid exposures to grid exposures, or to adjust exposure when changing from one grid ratio to another, you must remember the factor for each grid ratio:
2800
2801
2802To adjust exposure factors, you simply compare the old with the new:
280359. The main difference between direct capture and indirect capture DR is that
2804(A) direct capture/conversion has no scintillator
2805(B) direct capture/conversion uses a photo-stimulable phosphor
2806(C) in direct capture/conversion, light is detected by CCDs
2807(D) in direct capture/conversion, light is detected by TFTs
2808 --------------------------------- (A) One type of indirect-capture flat-panel detector uses cesium iodide or gadolinium oxysulfide as the scintillator, that is, which captures x-ray photons and emits light. That light is then transferred via a photodetector coupling agent—a CCD or TFT. In direct-capture flat-panel detector systems, x-ray energy is converted to an electrical signal in a single layer of material such as the semiconductor aSe. Electric charges are applied to both surfaces of the a-Se, electron-hole pairs are created, and charges are read by TFT arrays located on the surfaces. The electrical signal is transferred directly to the ADC. The number of TFTs is equal to the number of image pixels.
2809Thus, the direct-capture system eliminates the scintillator step required in indirect DR. Since selenium has a relatively low Z number (compared with gadolinium [Z 64] or cesium [Z 55]), a-Se detectors are made thicker to improve detection, thus compensating for the low x-ray absorption of selenium. There is no diffusion of electrons, so spatial resolution is not affected in this manner.
281060. The direction of electron travel in the x-ray tube is
2811(A) filament to cathode
2812(B) cathode to anode
2813(C) anode to focus
2814(D) anode to cathode
2815 --------------------------------- (B) The x-ray tube is a diode tube; that is, it has two electrodes—a negative and a positive. The cathode assembly is the negative terminal of the x-ray tube, and the anode is the positive terminal. Electrons are released by the cathode filament (thermionic emission) as it is heated to incandescence. When kilovoltage is applied, the electrons are driven across to the anode's focal spot. Upon sudden deceleration of electrons at the anode surface, x-rays are produced. Hence, electrons travel from cathode to anode within the x-ray tube.
281661. Which of the following technical changes would best serve to remedy the effect of very dissimilar tissue densities?
2817(A) Use of a small focal spot
2818(B) Use of a high-ratio grid
2819(C) High-kilovoltage exposure factors
2820(D) High milliampere-seconds exposure factors
2821 --------------------------------- (C) When tissue densities within a part are very dissimilar (e.g., chest x-ray), the radiographic result can be unacceptably high contrast. To "even out" these densities and produce a more appropriate scale of grays, exposure factors using high kilovoltage should be employed. Focal spot size is unrelated to image contrast. The higher the grid ratio, the higher is the contrast. Exposure factors using high milliampere-seconds generally result in unnecessary patient exposure.
282262. For the same FOV, spatial resolution will be improved using
2823(A) a smaller matrix
2824(B) a larger matrix
2825(C) fewer pixels
2826(D) shorter SID
2827 --------------------------------- (B) Field of view (FOV) refers to the area being viewed. The FOV can be increased or decreased. As the FOV is increased, the part being examined is magnified; as the FOV is decreased, the part returns closer to actual size. Pixel size is affected by changes in either the FOV or matrix size. For example, if the matrix size is increased, for example, from 256 × 256 to 512 × 512, pixel size must decrease. If FOV increases, pixel size must increase. Pixel size is inversely related to resolution. As pixel size decreases, resolution increases.
282863. Which of the following are methods of limiting the production of scattered radiation?
28291. Using moderate ratio grids
28302. Using the prone position for abdominal examinations
28313. Restricting the field size to the smallest practical size
2832(A) 1 and 2 only
2833(B) 1 and 3 only
2834(C) 2 and 3 only
2835(D) 1, 2, and 3
2836 --------------------------------- (C) If a fairly large patient is turned prone, the abdominal measurement will be significantly different from the AP measurement as a result of the effect of compression. Thus, the part is essentially "thinner," and less scattered radiation will be produced. If the patient remains supine and a compression band is applied, a similar effect will be produced. Beam restriction is probably the single most effective means of reducing the production of scattered radiation. Grid ratio affects the cleanup of scattered radiation; it has no effect on the production of scattered radiation.
283765. The absorption of useful radiation by a grid is called
2838(A) grid selectivity.
2839(B) grid cleanup.
2840(C) grid cutoff.
2841(D) latitude.
2842 --------------------------------- (C) Grids are used in radiography to absorb scattered radiation before it reaches the IR (grid "cleanup"), thus improving radiographic contrast. Contrast obtained with a grid compared with contrast without a grid is termed contrast-improvement factor. The greater the percentage of scattered radiation absorbed compared with absorbed primary radiation, the greater is the "selectivity" of the grid. If a grid absorbs an abnormally large amount of useful radiation as a result of improper centering, tube angle, or tube distance, grid cutoff occurs.
284367. Types of shape distortion include
28441. magnification
28452. elongation
28463. foreshortening
2847(A) 1 only
2848(B) 1 and 2 only
2849(C) 2 and 3 only
2850(D) 1, 2, and 3
2851 --------------------------------- (C) Size distortion (magnification) is inversely proportional to SID and directly proportional to OID. Increasing the SID and decreasing the OID decreases size distortion. Aligning the tube, part, and IR so that they are parallel reduces shape distortion. There are two types of shape distortion—elongation and foreshortening. Angulation of the part with relation to the IR results in foreshortening of the object. Tube angulation causes elongation of the object.
285268. For the same FOV, as the matrix size increases
28531. spatial resolution increases
28542. image quality increases
28553. pixel size decreases
2856(A) 1 only
2857(B) 1 and 2 only
2858(C) 2 and 3 only
2859(D) 1, 2, and 3
2860 --------------------------------- (D) Digital image storage is located in a pixel, which is a two-dimensional "picture element," measured in the "XY" direction. The third dimension, "Z" direction, in the matrix of pixels is the depth that is referred to as the voxel (volume element). The depth of the block is the number of bits required to describe the gray level that each pixel can take on—known as the bit depth.
2861The matrix is the number of pixels in the XY direction. As matrix size increases, for a fixed FOV, pixel size is smaller and better spatial resolution results. An electronic/digital image is formed by a matrix of pixels in rows and columns. A matrix having 512 pixels in each row and column is a 512 × 512 matrix (a typical CT image).
2862The term FOV is used to describe how much of the patient is included in the matrix. Either the matrix or the FOV can be changed without one affecting the other, but changes in either will change pixel size. As FOV increases, for a fixed matrix size, the size of each pixel increases and spatial resolution decreases. Fewer and larger pixels result in a poor-resolution "pixelly" or "mosaicked" image, that is, one in which you can actually see the individual pixel boxes.
286369. During CR imaging, the latent image present on the PSP is changed to a computerized image by the
2864(A) PSP
2865(B) Scanner-reader
2866(C) ADC
2867(D) helium-neon laser
2868 --------------------------------- (C) The exposed CR cassette is placed into the CR scanner/reader, where the PSP (SPS) is removed automatically. The latent image appears as the PSP is scanned by a narrow, high-intensity helium-neon laser to obtain the pixel data. As the plate is scanned in the CR reader, it releases a violet light—a process referred to as photostimulated luminescence (PSL). The luminescent light is converted to electrical energy representing the analog image. The electrical energy is sent to an analog-to-digital converter (ADC), where it is digitized and becomes the digital image that is displayed eventually (after a short delay) on a high-resolution monitor and/or printed out by a laser printer. The digitized images can also be manipulated in postprocessing, transmitted electronically, and stored/archived.
286970. All the following are related to recorded detail except
2870(A) milliamperage
2871(B) focal-spot size
2872(C) SID
2873(D) OID
2874 --------------------------------- (A) The focal-spot size selected will determine the amount of focal-spot, or geometric, blur produced in the image. OID and SID are responsible for image magnification and hence recorded detail. The milliamperage is unrelated to recorded detail; it affects only the quantity of x-ray photons produced and thus the radiographic density.
287571. A satisfactory radiograph was made using a 36-in. SID, 12 mAs, and a 12:1 grid. If the examination will be repeated at a distance of 42 in. and using a 5:1 grid, what should be the new milliampere-seconds value to maintain the original density?
2876(A) 5.6
2877(B) 6.5
2878(C) 9.7
2879(D) 13
2880 --------------------------------- (B) According to the density-maintenance formula, if the SID is changed to 42 in., 16.33 mAs is required to maintain the original radiographic density:
2881
2882
2883Thus, mAs at 42 in. SID. Then, to compensate for changing from a 12:1 grid to a 5:1 grid, the milliampere-seconds value becomes 6.53 mAs:
2884
2885
2886Thus, x 6.53 mAs with 5:1 grid at 42 in. SID. Hence, 6.53 mAs is required to produce an image density similar to that of the original radiograph. The following are the factors used for milliampere-seconds conversion from non-grid to grid:
288772. Of the following groups of exposure factors, which will produce the most radiographic density?
2888(A) 400 mA, 30 ms, 72-in. SID
2889(B) 200 mA, 30 ms, 36-in. SID
2890(C) 200 mA, 60 ms, 36-in. SID
2891(D) 400 mA, 60 ms, 72-in. SID
2892 --------------------------------- (C) The formula is used to determine each milliampere-second setting (remember to first change milliseconds to seconds). The greatest radiographic density will be produced by the combination of highest milliampere-seconds value and shortest SID. The groups in choices (B) and (D) should produce identical radiographic density, according to the inverse-square law, because group (D) includes twice the distance and 4 times the milliampere-seconds value of group (B). The group in (A) has twice the distance of the group in (B) but only twice the milliampere-seconds; therefore, it has the least density. The group in (C) has the same distance as the group in (B) and twice the milliampere-seconds, making group in (C) the group of technical factors that will produce the greatest radiographic density.
289373. Which of the following groups of exposure factors will produce the shortest scale of contrast?
2894(A) 200 mA, 0.08 second, 95 kV, 12:1 grid
2895(B) 500 mA, 0.03 second, 70 kV, 8:1 grid
2896(C) 300 mA, 0.05 second, 95 kV, 8:1 grid
2897(D) 600 mA, 1/40 seconds, 70 kV, 6:1 grid
2898 --------------------------------- (B) Of the given factors, kilovoltage and grid ratio will have a significant effect on radiographic contrast. Remember that the milliampere-seconds value has no effect on contrast scale. Because a combination of lower kilovoltage and a higher-ratio grid will allow the least amount of scattered radiation to reach the IR, thereby producing fewer gray tones, (B) is the best answer. (D) also uses low kilovoltage, but the grid ratio is lower—allowing more scatter to reach the IR (therefore, longer-scale contrast).
289974. Pathologic or abnormal conditions that would require a decrease in exposure factors include all of the following except
2900(A) osteoporosis
2901(B) osteomalacia
2902(C) emphysema
2903(D) pneumonia
2904 --------------------------------- D
290575. Which of the following is likely to contribute to the radiographic contrast present on the finished radiograph?
29061. Atomic number of tissues radiographed
29072. Any pathologic processes
29083. Degree of muscle development
2909(A) 1 and 2 only
2910(B) 1 and 3 only
2911(C) 2 and 3 only
2912(D) 1, 2, and 3
2913 --------------------------------- (D) The radiographic subject, the patient, is composed of many different tissue types that have varying densities, resulting in varying degrees of photon attenuation and absorption. The atomic number of the tissues under investigation is directly related to their attenuation coefficient. This differential absorption contributes to the various shades of gray (scale of radiographic contrast) on the finished radiograph. Normal tissue density may be altered significantly in the presence of pathologic processes. For example, destructive bone disease can cause a dramatic decrease in tissue density (and subsequent increase in radiographic density). Abnormal accumulation of fluid (as in ascites) will cause a significant increase in tissue density. Muscle atrophy or highly developed muscles similarly will decrease or increase tissue density.
291476. Which of the following factors influence(s) the production of scattered radiation?
29151. Kilovoltage level
29162. Tissue density
29173. Size of field
2918(A) 1 only
2919(B) 1 and 2 only
2920(C) 1 and 3 only
2921(D) 1, 2, and 3
2922 --------------------------------- (D) As photon energy (kV) increases, so does the production of scattered radiation. The greater the density of the irradiated tissues, the greater is the production of scattered radiation. As the size of the irradiated field increases, there is an increase in the volume of tissue irradiated, and the percentage of scatter again increases. Beam restriction is the single most important way to limit the amount of scattered radiation produced.
292377. A 15% decrease in kilovoltage accompanied by a 50% increase in milliampere-seconds will result in a(n)
2924(A) shorter scale of contrast
2925(B) increase in exposure latitude
2926(C) increase in radiographic density
2927(D) decrease in recorded detail
2928 --------------------------------- (A) A 15% decrease in kilovoltage with a 50% increase in milliampere-seconds produces an image similar to the original but with some obvious differences. The overall blackness (radiographic density) is doubled because of the increase in milliampere-seconds. This increase in blackness is compensated for by the loss of gray shades (i.e., shorter scale contrast) from the decreased kilovoltage. The decrease in kilovoltage also decreases exposure latitude; there is less margin for error in lower-kilovoltage ranges. Recorded detail is unaffected by changes in kilovoltage.
292978. Which of the following factors impact(s) recorded detail?
29301. Focal-spot size
29312. Subject motion
29323. SOD
2933(A) 1 and 2 only
2934(B) 1 and 3 only
2935(C) 2 and 3 only
2936(D) 1, 2, and 3
2937 --------------------------------- (D) Focal-spot size affects recorded detail by its effect on focal-spot blur: The larger the focal-spot size, the greater is the blur produced. Recorded detail is affected significantly by distance changes because of their effect on magnification. As SID increases and as OID decreases, magnification decreases and recorded detail increases. SOD is determined by subtracting OID from SID.
293879. Which of the following is (are) tested as part of a quality assurance (QA) program?
29391. Beam alignment
29402. Reproducibility
29413. Linearity
2942(A) 1 only
2943(B) 1 and 2 only
2944(C) 1 and 3 only
2945(D) 1, 2, and 3
2946 --------------------------------- (D) Each of the three is included in a good QA program. Beam alignment must be accurate to within 2% of the SID. Reproducibility means that repeated exposures at a given technique must provide consistent intensity. Linearity means that a given milliampere-second setting, using different milliampere stations with appropriate exposure-time adjustments, will provide consistent intensity.
294780. Focal-spot blur is greatest
2948(A) directly along the course of the central ray
2949(B) toward the cathode end of the x-ray beam
2950(C) toward the anode end of the x-ray beam
2951(D) as the SID is increased
2952 --------------------------------- (B) Focal-spot blur, or geometric blur, is caused by photons emerging from a large focal spot. The actual focal spot is always larger than the effective (or projected) focal spot, as illustrated by the line-focus principle. In addition, the effective focal-spot size varies along the longitudinal tube axis, being greatest in size at the cathode end of the beam and smallest at the anode end of the beam. Because the projected focal spot is greatest at the cathode end of the x-ray tube, geometric blur is also greatest at the corresponding part (cathode end) of the radiograph.
295381. How are mAs and patient dose related?
2954(A) mAs and patient dose are inversely proportional.
2955(B) mAs and patient dose are directly proportional.
2956(C) mAs and patient dose are unrelated.
2957(D) mAs and patient dose are inversely related.
2958 --------------------------------- (B) The milliampere-seconds value regulates the number of x-ray photons produced at the target and thus regulates patient dose. If the milliampere-seconds is doubled, dose is doubled; therefore, mAs and patient dose are directly proportional.
295982. Image plate front material can be made of which of the following?
29601. Carbon fiber
29612. Magnesium
29623. Lead
2963(A) 1 only
2964(B) 1 and 2 only
2965(C) 1 and 3 only
2966(D) 1, 2, and 3
2967 --------------------------------- (B) The image plate front material must not attenuate the remnant beam yet must be sturdy enough to withstand daily use. Bakelite has long been used as the material for tabletops and IR fronts, but now it has been replaced largely by magnesium and carbon fiber. Lead would not be a suitable material because it would absorb the remnant beam, and no image would be formed.
296883. Which of the following pathologic conditions would require a decrease in exposure factors?
2969(A) Congestive heart failure
2970(B) Pneumonia
2971(C) Emphysema
2972(D) Pleural effusion
2973 --------------------------------- (C) Emphysema is abnormal distension of the pulmonary alveoli (or tissue spaces) with air. The presence of abnormal amounts of air makes a decrease from normal exposure factors necessary to avoid excessive density. Congestive heart failure, pneumonia, and pleural effusion all involve abnormal amounts of fluid in the chest and, therefore, would require an increase in exposure factors.
297484. If a radiograph exposed using a 12:1 ratio grid exhibits increased brightness/loss of density at its lateral edges, it is probably because the
2975(A) SID was too great
2976(B) grid failed to move during the exposure
2977(C) x-ray tube was angled in the direction of the lead strips
2978(D) central ray was off-center
2979 --------------------------------- (A) If the SID is above or below the recommended focusing distance, the primary beam will not coincide with the angled lead strips at the lateral edges. Consequently, there will be absorption of the primary beam, termed grid cutoff. If the grid failed to move during the exposure, there would be grid lines throughout. Central ray angulation in the direction of the lead strips is appropriate and will not cause grid cutoff. If the central ray were off-center, there would be uniform loss of density.
298085. Practice(s) that enable the radiographer to reduce the exposure time required for a particular image include
29811. use of a higher milliamperage
29822. use of a higher kilovoltage
29833. use of a higher ratio grid
2984(A) 1 only
2985(B) 1 and 2 only
2986(C) 2 and 3 only
2987(D) 1, 2, and 3
2988 --------------------------------- (B) If it is desired to reduce the exposure time for a particular radiograph, as it might be when radiographing patients who are unable to cooperate fully, the milliamperage must be increased sufficiently to maintain the original milliampere-seconds value and thus image density/brightness. A higher kilovoltage could be useful because it would allow further reduction of the milliampere-seconds (exposure time) according to the 15% rule. Changing grid ratio is unrelated to desired changes in exposure time. Use of a higher-ratio grid would only necessitate an increase in mAs and not likely a decrease in exposure time.
298986. If 400 mA, 10 ms, and 90 kV were used for a particular exposure using three-phase, 12-pulse equipment, which of the following exposure changes would be most appropriate for use on single-phase equipment to produce a similar image?
2990(A) Use 200 mA
2991(B) Use 20 mAs
2992(C) Use 70 kV
2993(D) Use 0.02 second
2994 --------------------------------- (D) With three-phase equipment, the voltage never drops to zero, and x-ray intensity is significantly greater. When changing from single-phase to three-phase, six-pulse equipment, two-thirds of the original milliampere-seconds value is required to produce a radiograph with similar density. When changing from single-phase to three-phase, 12-pulse equipment, only half the original milliampere-seconds value is required. In this problem, we are changing from three-phase, 12-pulse to single-phase equipment; therefore, the milliampere-seconds value should be doubled (from 4-8 mAs).
299587. Which of the following materials may be used as grid interspace material?
29961. Lead
29972. Plastic
29983. Aluminum
2999(A) 1 only
3000(B) 1 and 2 only
3001(C) 2 and 3 only
3002(D) 1, 2, and 3
3003 --------------------------------- (C) A grid is composed of alternate strips of lead and interspace material. The lead strips serve to trap scattered radiation before it fogs the IR. The interspace material must be radiolucent; plastic or sturdier aluminum usually is used. Cardboard was used in the past as interspace material, but it had the disadvantage of being affected by humidity (moisture).
300489. Which of the following can impact the visibility of the anode heel effect?
30051. SID
30062. IR size
30073. Focal spot size
3008(A) 1 only
3009(B) 1 and 2 only
3010(C) 2 and 3 only
3011(D) 1, 2, and 3
3012 --------------------------------- (B) Because the focal spot (track) of an x-ray tube is along the anode's beveled edge, photons produced at the target are able to diverge considerably toward the cathode end of the x-ray tube but are absorbed by the heel of the anode at the opposite end of the tube. This results in a greater number of x-ray photons distributed toward the cathode end, which is known as the anode heel effect. The effect of this restricting heel is most pronounced when the x-ray photons are required to diverge more, as would be the case with short SID, large-size IRs and steeper (smaller) target angles.
301390. An increase in the kilovoltage applied to the x-ray tube increases the
30141. x-ray wavelength
30152. exposure rate
30163. patient absorption
3017(A) 1 only
3018(B) 2 only
3019(C) 2 and 3 only
3020(D) 1, 2, and 3
3021 --------------------------------- (B) As the kilovoltage is increased, a greater number of electrons are driven across to the anode with greater force. Therefore, as energy conversion takes place at the anode, more high-energy (short-wavelength) photons are produced. However, because they are higher-energy photons, there will be less patient absorption.
302291. Which of the following statements about histograms is/are true?
30231. A histogram illustrates pixel value distribution.
30242. There is a default histogram for each/different body parts.
30253. A histogram is representative of the image grayscale.
3026(A) 1 only
3027(B) 1 and 2 only
3028(C) 2 and 3 only
3029(D) 1, 2, and 3
3030 --------------------------------- (D) In digital imaging, as in film/screen radiography, there are numerous density/brightness values that represent various tissue densities (i.e., x-ray attenuation properties), for example, bone, muscle, fat, blood-filled organs, air/gas, metal, contrast media, and pathologic processes. In CR, the CR scanner/reader recognizes all these values and constructs a representative grayscale histogram of them, corresponding to the anatomic characteristics of the imaged part. Thus, all PA chest histograms are similar, all lateral chest histograms are similar, all pelvis histograms are similar, etc.
3031A histogram is a graphic representation of pixel value distribution. The histogram is an analysis and graphic representation of all the densities from the PSP screen, demonstrating the quantity of exposure, the number of pixels, and their value. Histograms are unique to each body part imaged.
3032Histogram appearance and patient dose can be affected by the radiographer's knowledge and skill using digital imaging, in addition to their degree of accuracy in positioning and centering. Collimation is exceedingly important to avoid histogram analysis errors. Lack of adequate collimation can result in signals outside the anatomic area being included in the exposure data recognition/histogram analysis. This can result in a variety of histogram analysis errors including excessively light, dark, or noisy images. Poor collimation can affect exposure level and exposure latitude; these changes are reflected in the images' informational numbers ("S number," "exposure index," etc.).
3033Other factors affecting histogram appearance, and therefore these informational numbers, include selection of the correct processing algorithm (e.g., chest vs. femur vs. cervical spine), changes in scatter, source-to-image-receptor distance (SID), object-to-image-receptor distance (OID), and collimation—in short, anything that affects scatter and/or dose.
303492. Which of the following is the correct order of radiographic film processing?
3035(A) Developer, wash, fixer, dry
3036(B) Fixer, wash, developer, dry
3037(C) Developer, fixer, wash, dry
3038(D) Fixer, developer, wash, dry
3039 --------------------------------- (C) During automatic processing (Figure 4-33), radiographic film is first immersed in the developer solution, which functions to reduce the exposed silver bromide crystals in the film emulsion to black metallic silver (which constitutes the image). Next, the film goes directly into the fixer, which functions to remove the unexposed silver bromide crystals from the emulsion. The film then is transported to the wash tank, where chemicals are removed from the film, and then into the dryer section, where it is dried before leaving the processor.
304093. If the radiographer is unable to achieve a short OID because of the structure of the body part or patient condition, which of the following adjustments can be made to minimize magnification distortion?
3041(A) A smaller focal-spot size should be used.
3042(B) A longer SID should be used.
3043(C) A shorter SID should be used.
3044(D) A lower-ratio grid should be used.
3045 --------------------------------- (B) An increase in SID will help to decrease the effect of excessive OID. For example, in the lateral projection of the cervical spine, there is normally a significant OID that would result in obvious magnification at a 40-in. SID. This effect is decreased by the use of a 72-in. SID. However, especially with larger body parts, increased SID usually requires a significant increase in exposure factors. Focal-spot size and grid ratio are unrelated to magnification.
304694. The reduction in x-ray photon intensity as the photon passes through material is termed
3047(A) absorption
3048(B) scattering
3049(C) attenuation
3050(D) divergence
3051 --------------------------------- (C) Absorption occurs when an x-ray photon interacts with matter and disappears, as in the photoelectric effect. Scattering occurs when there is partial transfer of energy to matter, as in the Compton effect. The reduction in the intensity of an x-ray beam as it passes through matter is called attenuation.
305296. Exposure rate will decrease with an increase in
30531. SID
30542. kilovoltage
30553. focal spot size
3056(A) 1 only
3057(B) 1 and 2 only
3058(C) 2 and 3 only
3059(D) 1, 2, and 3
3060 --------------------------------- (A) Exposure rate decreases with an increase in SID according to the inverse-square law of radiation. The quantity of x-ray photons produced at the focal spot is the function of milliampere-seconds. The quality (i.e., wavelength, penetration, and energy) of x-ray photons produced at the target is the function of kilovoltage. The kilovoltage also has an effect on exposure rate because an increase in kilovoltage will increase the number of highenergy x-ray photons produced at the anode.
306197. Which of the following pathologic conditions probably will require a decrease in exposure factors?
3062(A) Osteomyelitis
3063(B) Osteoporosis
3064(C) Osteosclerosis
3065(D) Osteochondritis
3066 --------------------------------- (B) Osteoporosis is a condition, often seen in the elderly, marked by increased porosity and softening of bone. The bones are much less dense, and thus a decrease in exposure is required. Osteomyelitis and osteochondritis are inflammatory conditions that usually have no effect on bone density. Osteosclerosis is abnormal hardening of the bone, and an increase in exposure factors would be required.
306798. Diagnostic x-rays are generally associated with
3068(A) high frequency and long wavelength
3069(B) high frequency and short wavelength
3070(C) low frequency and long wavelength
3071(D) low frequency and short wavelength
3072 --------------------------------- (B) Electromagnetic radiation can be described as wave-like fluctuations of electric and magnetic fields. There are many kinds of electromagnetic radiation; visible light, microwaves, and radio waves, as well as x-ray and gamma rays, are all part of the electromagnetic spectrum. All the electromagnetic radiations have the same velocity, that is, 3 × 108 m/s (1,86,000 miles per second); however, they differ greatly in wavelength and frequency. Wavelength refers to the distance between two consecutive wave crests. Frequency refers to the number of cycles per second; its unit of measurement is hertz (Hz), which is equal to 1 cycle per second. Frequency and wavelength are closely associated with the relative energy of electromagnetic radiations. More energetic radiations have shorter wavelength and higher frequency. The relationship among frequency, wavelength, and energy is graphically illustrated in the electromagnetic spectrum.
3073Some radiations are energetic enough to rearrange atoms in materials through which they pass, and they can therefore be hazardous to living tissue. These radiations are called ionizing radiation because they have the energetic potential to break apart electrically neutral atoms, resulting in the production of negative and/or positive ions.
307499. A film/screen image exhibiting insufficient density might be attributed to
30751. inadequate kilovoltage
30762. inadequate SID
30773. grid cutoff
3078(A) 1 only
3079(B) 1 and 2 only
3080(C) 1 and 3 only
3081(D) 1, 2, and 3
3082 --------------------------------- (C) As kilovoltage is reduced, the number of high-energy photons produced at the target is reduced; therefore, a decrease in radiographic density occurs. If a grid has been used improperly (off-centered or out of focal range), the lead strips will absorb excessive amounts of primary radiation, resulting in grid cutoff and loss of radiographic density. If the SID is inadequate (too short), an increase in radiographic density will occur.
3083100. If a lateral projection of the chest is being performed on an asthenic patient and the outer photocells are selected, what is likely to be the outcome?
3084(A) Decreased density
3085(B) Increased density
3086(C) Scattered radiation fog
3087(D) Motion blur
3088 --------------------------------- (A) If a lateral projection of the chest is being performed on an asthenic patient and the outer photocells are selected incorrectly, the outcome is likely to be an underexposed radiograph. The patient is thin, and the lateral cells have no tissue superimposed on them. Therefore, as soon as the lateral photocells detect radiation (which will be immediately), the exposure will be terminated, giving the lateral chest insufficient exposure.
3089101. Which of the following devices is used to overcome severe variation in patient anatomy or tissue density, providing more uniform radiographic density?
3090(A) Compensating filter
3091(B) Grid
3092(C) Collimator
3093(D) Added filtration
3094 --------------------------------- (A) A compensating filter is used when the part to be radiographed is of uneven thickness or density (in the chest, mediastinum vs. lungs). The filter (made of aluminum or lead acrylic) is constructed in such a way that it will absorb much of the primary radiation that would expose the low-tissue-density area while allowing the primary radiation to pass unaffected to the high-tissue-density area. A collimator is used to decrease the production of scattered radiation by limiting the volume of tissue irradiated. The grid functions to trap scattered radiation before it reaches the IR, thus reducing scattered radiation fog. Added filtration addresses patient protection, decreasing patient dose.
3095102. What are the effects of scattered radiation on a radiographic image?
30961. It produces fog.
30972. It increases contrast.
30983. It increases grid cutoff.
3099(A) 1 only
3100(B) 2 only
3101(C) 1 and 2 only
3102(D) 1, 2, and 3
3103 --------------------------------- (A) Scattered radiation is produced as x-ray photons travel through matter, interact with atoms, and are scattered (change direction). If these scattered rays are energetic enough to exit the body, they will strike the IR from all different angles. They, therefore, do not carry useful information and merely produce a flat, gray (low-contrast) fog over the image. Grid cutoff increases contrast and is caused by an improper relationship between the x-ray tube and the grid, resulting in absorption of some of the useful/primary beam.
3104103. Which of the following groups of exposure factors would be most appropriate to control involuntary motion?
3105(A) 400 mA, 0.03 second
3106(B) 200 mA, 0.06 second
3107(C) 600 mA, 0.02 second
3108(D) 100 mA, 0.12 second
3109 --------------------------------- (C) Control of motion, both voluntary and involuntary, is an important part of radiography. Patients are unable to control certain types of motion, such as heart action, peristalsis, and muscle spasm. In these circumstances, it is essential to use the shortest possible exposure time in order to have a "stop action" effect.
3110104. Methods that help to reduce the production of scattered radiation include using
31111. compression
31122. beam restriction
31133. a grid
3114(A) 1 and 2 only
3115(B) 1 and 3 only
3116(C) 2 and 3 only
3117(D) 1, 2, and 3
3118 --------------------------------- (A) Limiting the size of the irradiated field is a most effective method of decreasing the production of scattered radiation. The smaller the volume of tissue irradiated, the smaller is the amount of scattered radiation generated; this can be accomplished using compression (prone position instead of supine or a compression band). Use of a grid does not affect the production of scattered radiation but rather removes it once it has been produced.
3119105. The function(s) of the developer in film processing is (are) to
31201. remove the unexposed silver bromide crystals
31212. change the exposed silver bromide crystals to black metallic silver
31223. harden the emulsion
3123(A) 1 only
3124(B) 2 only
3125(C) 1 and 3 only
3126(D) 2 and 3 only
3127 --------------------------------- (B) X-ray film processing consists of four parts: development, fixing, wash, and dry. Developing agents change the exposed silver bromide crystals (latent image) to black metallic silver, thus producing a manifest image. The fixer solution removes the unexposed silver bromide crystals from the emulsion and hardens the gelatin emulsion, thus ensuring permanence of the radiograph.
3128106. Although the stated focal spot size is measured directly under the actual focal spot, focal spot size actually varies along the length of the x-ray beam. At which portion of the x-ray beam is the effective focal spot the largest?
3129(A) At its outer edge
3130(B) Along the path of the central ray
3131(C) At the cathode end
3132(D) At the anode end
3133 --------------------------------- (C) X-ray tube targets are constructed according to the line-focus principle—the focal spot is angled (usually, 12-17 degrees) to the vertical (Figure 4-34). As the actual focal spot is projected downward, it is foreshortened; thus, the effective focal spot is always smaller than the actual focal spot. As it is projected toward the cathode end of the x-ray beam, the effective focal spot becomes larger and approaches the actual size. As it is projected toward the anode end, it gets smaller because of the anode heel effect.
3134108. Which of the following affect(s) both the quantity and the quality of the primary beam?
31351. Half-value layer (HVL)
31362. Kilovoltage (kV)
31373. Milliamperage (mA)
3138(A) 1 only
3139(B) 2 only
3140(C) 1 and 2 only
3141(D) 1, 2, and 3
3142 --------------------------------- (C) Kilovoltage and the HVL affect both the quantity and the quality of the primary beam. The principal qualitative factor for the primary beam is kilovoltage, but an increase in kilovoltage will also create an increase in the number of photons produced at the target. HVL is defined as the amount of material necessary to decrease the intensity of the beam to one-half its original value, thereby effecting a change in both beam quality and quantity. The milliampere-seconds value is adjusted to regulate the number of x-ray photons produced at the target. X-ray-beam quality is unaffected by changes in milliampere-seconds.
3143109. The intensity of ionizing radiation decreases as
3144(A) distance from the source of radiation decreases
3145(B) distance from the source of radiation increases
3146(C) frequency increases
3147(D) wavelength decreases
3148 --------------------------------- (B) As distance from a light source increases, the light diverges and covers a larger area; the quantity of light available per unit area becomes less and less as distance increases. The intensity (quantity) of light decreases according to the inverse square law, that is, the intensity of light at a particular distance from its source is inversely proportional to the square of the distance. For example, if you decreased the distance between a book you were reading and your illuminating lamp from 6 to 3 feet, you would have four times as much light available.
3149Similarly, SID has a significant impact on x-ray beam intensity. As the distance between the x-ray tube and IR increases, exposure rate decreases according to the inverse square law.
3150110. Which of the following would be useful for an examination of a patient suffering from Parkinson's disease?
31511. Short exposure time
31522. Decreased SID
31533. Compensating filtration
3154(A) 1 only
3155(B) 1 and 2 only
3156(C) 1 and 3 only
3157(D) 1, 2, and 3
3158 --------------------------------- (A) The shortest possible exposure should be used as a matter of routine. Parkinson disease is characterized by uncontrollable tremors, and the resulting unsharpness can destroy image resolution/detail. A short exposure time is essential. That can be achieved by increasing the mA or the kV—AEC will react with a shorted exposure time. SID and compensating filtration are unrelated to the problem and are not indicated here.
3159111. Underexposure of a radiograph can be caused by all the following except insufficient
3160(A) milliamperage (mA)
3161(B) exposure time
3162(C) Kilovoltage
3163(D) SID
3164 --------------------------------- (D) Insufficient milliamperage and/or exposure time will result in lack of radiographic density. Insufficient kilovoltage will result in underpenetration and excessive contrast. Insufficient SID, however, will result in increased exposure rate and radiographic overexposure.
3165112. Potential digital image postprocessing tasks include
31661. PACS
31672. annotation
31683. inversion/reversal
3169(A) 1 only
3170(B) 1 and 2 only
3171(C) 2 and 3 only
3172(D) 1, 2, and 3
3173 --------------------------------- (C) Digital image postprocessing provides the opportunity for image optimization. Image annotation permits placement of labels, arrow indicators, etc. Windowing allows adjustment of image contrast d/or brightness to diagnostic requirements. Contrast scale enhancement is the most valuable tool in digital imaging. Image minification, with larger matrix sizes, enables us to see tiny anatomic details and improve spatial resolution. Image inversion, or reversal, provides a different perspective by changing white to black and black to white. Image flip also provides another perspective by enabling us to rotate the image. Edge enhancement is useful for small and high-contrast tissues. Other postprocessing functions include highlighting, zoom, pan, and scroll. The pixel shift feature is important in DSA. Image subtraction is used to enhance contrast. If the part moves during acquisition of serial images, misregistration occurs, making the required exact superimposition impossible. Pixel shift is a function that can correct misregistration. Another emerging postprocessing task used in diagnostic functions is determining numeric pixel value for particular ROI (region of interest). This feature has proved useful in bone densitometry, renal calculus recognition, and calcified lung nodule identification.
3174113. An anteroposterior (AP) projection of the femur was made using 300 mA, 0.03 second, 76 kV, 40-in. SID, 1.2-mm focal spot, and a 400-speed film-screen system. With all other factors remaining constant, which of the following exposure times would be required to maintain radiographic density/brightness at a 44-in. SID using 500 mA?
3175(A) 12 ms
3176(B) 22 ms
3177(C) 30 ms
3178(D) 36 ms
3179 --------------------------------- (B) The original milliampere-seconds value was 9 (300 mA × 0.03 second). Using the density-maintenance formula, the new milliampere-seconds value must be determined for the distance change from 40 to 44 in. of the SID:
3180
3181
3182Thus, (11) mAs at 44-in. SID. Then, if 500 is the new milliamperage, we must determine what exposure time is required to achieve 8.1 mAs:
3183
3184
3185Thus, second (22 ms) at 500 mA and 44-in. SID.
3186114. An AP radiograph of the femur was made using 300 mA, 30 ms, 76 kV, 40-in. SID, and 1.2-mm focal spot. With all other factors remaining constant, which of the following exposure times would be required to maintain brightness/density using 87 kV and the addition of a 12:1 grid?
3187(A) 38 ms
3188(B) 60 ms
3189(C) 75 ms
3190(D) 150 ms
3191 --------------------------------- (C) A 15% increase in kilovoltage was made, increasing the kilovoltage to 87 kV. Because the kilovoltage change effectively doubles the density, the milliampere-seconds value now must be cut in half (from 9 to 4.5 mAs) to compensate. Grids are used to absorb scattered radiation from the remnant beam before it can contribute to the x-ray image. Because the grid removes scattered radiation (and some useful photons as well) from the beam, an increase in exposure factors is required. The amount of increase depends on the grid ratio; the higher the grid ratio, the higher is the correction factor. The correction factor for a 12:1 grid is 5; therefore, the milliampere-seconds value (4.5) is multiplied by 5 to arrive at the new required milliampere-seconds value (22.5). Using the milliampere-seconds equation , it is determined that 0.15 second will be required at 300 mA:
3192115. HVL is affected by the amount of
31931. kVp
31942. beam filtration
31953. tissue density
3196(A) 1 only
3197(B) 1 and 2 only
3198(C) 2 and 3 only
3199(D) 1, 2, and 3
3200 --------------------------------- (B) Manufacturers of x-ray equipment must follow guidelines that state maximum x-ray output at specific distances, total quantities of filtration, positive beam limitation, and other guidelines. Radiographers must practice safe principles of operation; preventive maintenance and quality control (QC) checks must be performed at specific intervals to ensure continued safe equipment performance. Radiologic QC involves monitoring and regulating the variables associated with image production and patient care.
3201HVL testing provides beam quality information that is different from that obtained from kV testing. HVL is defined as the thickness of any absorber that will reduce x-ray beam intensity to one-half its original value. It is determined by measuring the beam intensity without an absorber and then recording the intensity as successive millimeters of aluminum are added to the radiation field. It is influenced by the type of rectification, total filtration, and kV. An x-ray tube HVL should remain almost constant. If HVL decreases, it is an indication of a decrease in the actual kV. If the HVL increases, it indicates the deposition of vaporized tungsten on the inner surface of the glass envelope (as a result of tube aging) or an increase in the actual kV.
3202116. In a posteroanterior (PA) projection of the chest being used for cardiac evaluation, the heart measures 14.7 cm between its widest points. If the magnification factor is known to be 1.2, what is the actual diameter of the heart?
3203(A) 10.4 cm
3204(B) 12.25 cm
3205(C) 13.5 cm
3206(D) 17.64 cm
3207 --------------------------------- (B) The formula for magnification factor (MF) = image size/object size. In the stated problem, the anatomic measurement is 14.7 cm, and the magnification factor is known to be 1.2. Substituting the known factors in the appropriate equation:
3208
3209
3210(actual anatomic size).
3211117. Bone densitometry is often performed to
32121. measure degree of bone (de) mineralization
32132. evaluate the results of osteoporosis treatment/therapy
32143. evaluate the condition of soft tissue adjacent to bone
3215(A) 1 only
3216(B) 1 and 2 only
3217(C) 2 and 3 only
3218(D) 1, 2, and 3
3219 --------------------------------- (B) DXA imaging is used to evaluate bone mineral density (BMD). Bone densitometry (i.e., DXA) can be used to evaluate bone mineral content of the body, or part of it, to diagnose osteoporosis or to evaluate the effectiveness of treatments for osteoporosis. It is the most widely used method of bone densitometry—it is low-dose, precise, and uncomplicated to use/perform. DXA uses two photon energies—one for soft tissue and one for bone. Since bone is denser and attenuates x-ray photons more readily, their attenuation is calculated to represent the degree of bone density. Soft tissue attenuation information is not used to measure bone density.
3220118. The differences between CR and DR include
32211. DR images are displayed immediately.
32222. DR has higher DQE and lower patient dose.
32233. DR uses IPs.
3224(A) 1 only
3225(B) 1 and 2 only
3226(C) 2 and 3 only
3227(D) 1, 2, and 3
3228 --------------------------------- (B) While CR utilizes traditional x-ray tables and IPs to enclose and protect the flexible PSP screen, DR requires the use of significantly different equipment. DR does not use IPs or a traditional x-ray table—it is a direct-capture/conversion, or indirect-capture/conversion, system of x-ray imaging. Besides eliminating IPs and their handling, DR affords the advantage of immediate display of the image (compared with CR's slightly delayed image display), and DR exposures can be lower because of the detector's higher DQE (i.e., ability to perceive and interact with x-ray photons). DR, like CR, also offers the advantage of image preview and postprocessing.
3229120. The process of "windowing" of digital images determines the image
3230(A) spatial resolution
3231(B) contrast
3232(C) pixel size
3233(D) matrix size
3234 --------------------------------- (B) The digital images' scale of contrast, or contrast resolution, can be changed electronically through leveling and windowing of the image. The level control determines the central or middensity of the scale of contrast, whereas the window control determines the total number of densities/grays (to the right and left of the central/middensity). Matrix and pixel sizes are related to (spatial) resolution of digital images.
3235121. What is the purpose of the thin layer of lead that is often located in the rear portion of an IP?
3236(A) To prevent crossover
3237(B) To increase speed
3238(C) To diffuse light photons
3239(D) To prevent scattered radiation fog
3240 --------------------------------- (D) The purpose of the thin layer of lead that is often located in the rear portion of an IP is to absorb x-ray photons that strike the rear of the IP and bounce back toward the PSP, resulting in scattered radiation fog. The thin layer of lead absorbs these x-ray photons and thus improves the radiographic image.
3241122. The purpose of the electroconductive layer of a CR PSP plate is to
3242(A) provide support to the PSP layer
3243(B) provide mechanical strength
3244(C) facilitate transportation through the scanner/reader
3245(D) provide better resolution
3246 --------------------------------- (C) The PSP plate within the CR cassette/IP has several layers. Its uppermost layer is a protective coat for the phosphor layer below. This layer affords durability and must be translucent to allow passage of photostimulable luminescent light. The phosphor layer is the "active" layer that responds to the x-ray photons that reach it. Under the phosphor layer is the electroconductive layer that serves to facilitate transportation through the scanner/reader and prevent image artifacts resulting from static electricity. Below the electroconductive layer is the plate support layer. Below the support layer is a light-shield layer that serves to prevent light from erasing image plate data or from approaching through the rear protective layer. Behind the light-shield layer is the rear protective layer of the PSP plate.
3247123. Which of the following combinations is most likely to be associated with quantum mottle?
3248(A) Decreased milliampere-seconds, decreased SID
3249(B) Increased milliampere-seconds, decreased kilovoltage
3250(C) Decreased milliampere-seconds, increased kilovoltage
3251(D) Increased milliampere-seconds, increased SID
3252 --------------------------------- (C) Quantum noise, or mottle, is a grainy appearance; it has a spotted or freckled appearance. It looks very similar to a low-resolution photograph/image that has been enlarged. Low mAs and high kV factors are most likely to be the cause of quantum noise/mottle. SID is unrelated to quantum noise.
3253124. What pixel size has a 2,048 × 2,048 matrix with a 60-cm FOV?
3254(A) 0.3 mm
3255(B) 0.5 mm
3256(C) 0.15 mm
3257(D) 0.03 mm
3258 --------------------------------- (A) In digital imaging, pixel size is determined by dividing the FOV by the matrix. In this case, the FOV is 60 cm; since the answer is expressed in millimeters, first change 60 cm to 600 mm. Then 600 divided by 2,048 equals 0.35 mm:
3259
3260
3261The FOV and matrix size are independent of one another; that is, either can be changed, and the other will remain unaffected. However, pixel size is affected by changes in either the FOV or matrix size. For example, if the matrix size is increased, pixel size decreases. If FOV increases, pixel size increases. Pixel size is inversely related to resolution. As pixel size increases, resolution decreases.
3262125. Which of the following possesses the widest dynamic range?
3263(A) Film/screen imaging
3264(B) Beam restriction
3265(C) AEC
3266(D) CR
3267 --------------------------------- (D) One of the biggest advantages of CR is the dynamic range, or latitude, it offers. The characteristic curve of x-ray film emulsion has a certain "range of correct exposure," limited by the toe and shoulder of the curve. In CR, there is a linear relationship between the exposure, given the PSP (SPS) and its resulting luminescence as it is scanned by the laser. This affords much greater exposure latitude, and technical inaccuracies can be effectively eliminated. Overexposure of up to 500% and underexposure of up to 80% are reported as recoverable, thus eliminating most retakes. This surely affords increased efficiency; however, this does not mean that images can be exposed arbitrarily. The radiographer must keep dose reduction in mind. The same exposure factors as screen-film systems, or less, generally are recommended for CR. Intensifying screens used in screen-film x-ray imaging tend to produce high contrast. The faster the screens, the higher is the contrast; higher contrast often is associated with decreased latitude. AEC refers to automatic exposure control and is unrelated to dynamic range or latitude.
3268126. Which of the following matrix sizes is most likely to produce the best image resolution?
3269(A) 128 × 128
3270(B) 512 × 512
3271(C) 1,024 × 1,024
3272(D) 2,048 × 2,048
3273 --------------------------------- (D) The matrix is the number of pixels in the xy direction. The larger the matrix size, the better is the image resolution. Typical image matrix sizes used in radiography are
3274
3275
3276A digital image is formed by a matrix of pixels in rows and columns. A matrix having 512 pixels in each row and column is a 512 × 512 matrix. The term field of view is used to describe how much of the patient (e.g., 150-mm diameter) is included in the matrix. The matrix or field of view can be changed without affecting the other, but changes in either will change pixel size. As in traditional radiography, spatial resolution is measured in line pairs per millimeter (lp/mm). As matrix size is increased, there are more and smaller pixels in the matrix and, therefore, improved spatial resolution. Fewer and larger pixels result in a poor-resolution "pixelly" image, that is, one in which you can actually see the individual pixel boxes.
3277128. Factors that determine recorded detail in digital imaging include
32781. part motion
32792. geometric factors
32803. spatial resolution
3281(A) 1 only
3282(B) 1 and 2 only
3283(C) 2 and 3 only
3284(D) 1, 2, and 3
3285 --------------------------------- (D) Factors influencing recorded detail in digital imaging are very much the same as those factors affecting recorded detail in analog imaging, that is, motion, geometric factors (focal spot size, OID, and SID), and spatial resolution. In analog imaging, spatial resolution is related to the speed of the imaging system (intensifying screen speed) and is significantly better than digital imaging resolution. The spatial resolution of direct digital systems, however, is fixed and is related to the detector element (DEL) size of the thin film transistor (TFT). The smaller the TFT DEL size, the better the spatial resolution. DEL size of 100 microns provides a spatial resolution of about 5 lp/mm (available only in some digital mammography systems). DEL size of 200 microns provides a spatial resolution of about 2.5 lp/mm (general radiography)—lower than that achieved with 400 speed intensifying screen system. A 100 speed intensifying screen system offers a spatial resolution of about 10 lp/mm—significantly greater than, and currently unachievable in, digital imaging. Spatial resolution in digital imaging is fixed, but it is very important that radiographers are alert to the opportunity they have to utilize and control the remaining recorded detail factors (motion and geometric factors).
3286129. Examples of health care informatics include
32871. HIS
32882. RIS
32893. PACS
3290(A) 1 only
3291(B) 1 and 2 only
3292(C) 2 and 3 only
3293(D) 1, 2, and 3
3294 --------------------------------- (D) Health care information technology, or health informatics, has ever-increasing application and use in the imaging sciences. PACS (Picture Archiving and Communication Systems) is used by health care facilities to economically store, archive, exchange, and transmit digital images from multiple imaging modalities. PACS replaces the need to manually file, retrieve, and transport film and film jackets.
3295RIS (Radiology Information Systems) and HIS (Hospital Information Systems) can be integrated with PACS for electronic health information storage. The purpose of HIS is to manage health care information and documents electronically, and to ensure data security and availability. RIS is a system for tracking radiological and imaging procedures. RIS is used for patient registration and scheduling, radiology workflow management, reporting and printout, manipulation and distribution and tracking of patient data, and billing. RIS complements HIS and is critical to competent workflow to radiologic facilities.
3296130. The exposure factors of 400 mA, 17 ms, and 82 kV produce a milliampere-seconds value of
3297(A) 2.35
3298(B) 6.8
3299(C) 23.5
3300(D) 68
3301 --------------------------------- (B) To calculate milliampere-seconds, multiply milliamperage times exposure time. In this case, 400 mA × 0.017 second . Careful attention to proper decimal placement will help to avoid basic math errors.
3302131. All the following statements regarding CR IPs are true except
3303(A) IPs do not contain radiographic film.
3304(B) IPs use no intensifying screens.
3305(C) IPs must exclude all white light.
3306(D) IPs function to protect the PSP.
3307 --------------------------------- (C) Externally, IPs (Image Plates) appear very much like traditional film-screen cassettes. However, the main function of an IP is to support and protect the PSP (SPS) that lies within the IP. IPs do not contain intensifying screens or film and, therefore, do not need to be lighttight. The photostimulable PSP is not affected by light.
3308132. The radiographic accessory used to measure the thickness of body parts in order to determine optimal selection of exposure factors is the
3309(A) fulcrum
3310(B) caliper
3311(C) densitometer
3312(D) ruler
3313 --------------------------------- (B) Radiographic technique charts are highly recommended for use with every x-ray unit. A technique chart identifies the standardized factors that should be used with that particular x-ray unit for various examinations/positions of anatomic parts of different sizes. To be used effectively, these technique charts require that the anatomic part in question be measured correctly with a caliper. A fulcrum is of importance in tomography; a densitometer is used in sensitometry and QA.
3314133. The x-ray image seen on the computer display monitor is a (an)
3315(A) analog image
3316(B) digital image
3317(C) phosphor image
3318(D) emulsion image
3319 --------------------------------- (A) Remnant x-rays emerging from the patient/part are converted to electrical signals. This is an analog image. These electrical signals are sent to the ADC (analog-to-digital converter) to be converted to digital data (in binary digits or bits). Then, the digital image data is transferred to a DAC (digital-to-analog converter) to be converted to a perceptible analog image on the display monitor. The monitor image can be manipulated, postprocessed, stored, or transmitted.
3320134. A focal-spot size of 0.3 mm or smaller is essential for
3321(A) small-bone radiography
3322(B) magnification radiography
3323(C) tomography
3324(D) fluoroscopy
3325 --------------------------------- (B) A fractional focal spot of 0.3 mm or smaller is essential for reproducing fine detail without focal-spot blurring in magnification radiography. As the object image is magnified, so will be any associated blur unless a fractional focal spot is used. Use of a fractional focal spot on a routine basis is unnecessary; it is not advised because it causes unnecessary wear on the x-ray tube and offers little radiographic advantage.
3326135. For which of the following examinations can the anode heel effect be an important consideration?
33271. Lateral thoracic spine
33282. AP femur
33293. Right anterior oblique (RAO) sternum
3330(A) 1 only
3331(B) 1 and 2 only
3332(C) 1 and 3 only
3333(D) 1, 2, and 3
3334 --------------------------------- (B) The heel effect is characterized by a variation in beam intensity that increases gradually from anode to cathode. This can be effectively put to use when performing radiographic examinations of large body parts with uneven tissue density. For example, the AP thoracic spine is thicker caudally than cranially, so the thicker portion is best placed under the cathode. However, in the lateral projection of the thoracic spine, the upper portion is thicker because of superimposed shoulders, and therefore, that portion is best placed under the cathode end of the beam. The femur is also uneven in density, particularly in the AP position, and can benefit from use of the heel effect. However, the sternum and its surrounding anatomy are fairly uniform in thickness and would not benefit from use of the anode heel effect. The anode heel effect is most pronounced when using large IRs at short SIDs and with an anode having a steep (small) target angle.
3335136. All the following have an impact on radiographic contrast except
3336(A) photon energy
3337(B) grid ratio
3338(C) OID
3339(D) focal-spot size
3340 --------------------------------- (D) As photon energy increases, more penetration and greater production of scattered radiation occur, producing a longer scale of contrast. As grid ratio increases, more scattered radiation is absorbed, producing a shorter scale of contrast. As OID increases, the distance between the part and the IR acts as a grid, and consequently, less scattered radiation reaches the IR, producing a shorter scale of contrast. Focal-spot size is related only to recorded detail.
3341137. A radiograph made with a parallel grid demonstrates decreased density on its lateral edges. This is most likely due to
3342(A) static electrical discharge
3343(B) the grid being off-centered
3344(C) improper tube angle
3345(D) decreased SID
3346 --------------------------------- (D) The lead strips in a parallel grid are parallel to one another and, therefore, are not parallel to the x-ray beam. The more divergent the x-ray beam, the more likely there is to be cutoff/decreased density at the lateral edges of the radiograph. This problem becomes more pronounced at short SIDs. If there were a centering or tube angle problem, there would be more likely to be a noticeable density loss on one side or the other.
3347139. A particular milliampere-seconds value, regardless of the combination of milliamperes and time, will reproduce the same radiographic density. This is a statement of the
3348(A) line-focus principle
3349(B) inverse-square law
3350(C) reciprocity law
3351(D) law of conservation of energy
3352 --------------------------------- (C) The reciprocity law states that a particular milliampere-seconds value, regardless of the milliamperage and exposure time used, will provide identical radiographic density. This holds true with direct exposure techniques, but it does fail somewhat with the use of intensifying screens. However, the fault is so slight as to be unimportant in most radiographic procedures.
3353140. OID is related to recorded detail in which of the following ways?
3354(A) Radiographic detail is directly related to OID.
3355(B) Radiographic detail is inversely related to OID.
3356(C) As OID increases, so does radiographic detail.
3357(D) OID is unrelated to radiographic detail.
3358 --------------------------------- (B) As the distance from the object to the IR (OID) increases, so does magnification distortion, thereby decreasing recorded detail. Some magnification is inevitable in radiography because it is not possible to place anatomic structures directly on the IR. However, our understanding of how to minimize magnification distortion is an important part of our everyday work.
3359141. If 300 mA has been selected for a particular exposure, what exposure time would be required to produce 6 mAs?
3360(A) 5 ms
3361(B) 10 ms
3362(C) 15 ms
3363(D) 20 ms
3364 --------------------------------- (D) Milliampere-seconds (mAs) is the exposure factor that regulates radiographic density. The equation used to determine mAs is . Substituting the known factors:
3365142. In digital imaging, as DEL size decreases
3366(A) brightness increases
3367(B) brightness decreases
3368(C) spatial resolution increases
3369(D) spatial resolution decreases
3370 --------------------------------- (C) Factors influencing recorded detail in digital imaging are very much the same as those factors affecting recorded detail in analog imaging, that is, motion, geometric factors (focal spot size, OID, and SID), and spatial resolution. In analog imaging, spatial resolution is related to the speed of the imaging system (intensifying screen speed) and is significantly better than digital imaging resolution. The spatial resolution of direct digital systems, however, is fixed and is related to the detector element (DEL) size of the thin film transistor (TFT). The smaller the TFT DEL size, the better the spatial resolution. DEL size of 100 microns provides a spatial resolution of about 5 lp/mm (available only in some digital mammography systems). DEL size of 200 microns provides a spatial resolution of about 2.5 lp/mm (general radiography)—lower than that achieved with 400 speed intensifying screen system. A 100 speed intensifying screen system offers a spatial resolution of about 10 lp/mm—significantly greater than, and currently unachievable in, digital imaging. Spatial resolution in digital imaging is fixed, but it is very important that radiographers are alert to the opportunity they have to utilize and control the remaining recorded detail factors (motion and geometric factors).
3371143. An increase in kilovoltage will serve to
3372(A) produce a longer scale of contrast
3373(B) produce a shorter scale of contrast
3374(C) decrease the radiographic density
3375(D) decrease the production of scattered radiation
3376 --------------------------------- (A) An increase in kilovoltage increases the overall average energy of the x-ray photons produced at the target, thus giving them greater penetrability. (This can increase the incidence of Compton interaction and, therefore, the production of scattered radiation.) Greater penetration of all tissues serves to lengthen the scale of contrast. However, excessive scattered radiation reaching the IR will cause a fog and carries no useful information.
3377144. The functions of automatic beam limitation devices include
33781. reducing the production of scattered radiation
33792. increasing the absorption of scattered radiation
33803. changing the quality of the x-ray beam
3381(A) 1 only
3382(B) 2 only
3383(C) 1 and 2 only
3384(D) 1, 2, and 3
3385 --------------------------------- (A) Beam restrictors function to limit the size of the irradiated field. In so doing, they limit the volume of tissue irradiated (thereby decreasing the percentage of scattered radiation generated in the part) and help to reduce patient dose. Beam restrictors do not affect the quality (energy) of the x-ray beam—that is, the function of kilovoltage and filtration. Beam restrictors do not absorb scattered radiation—that is a function of grids.
3386145. Recorded detail/resolution is inversely related to
33871. SID
33882. OID
33893. part motion
3390(A) 1 only
3391(B) 1 and 2 only
3392(C) 2 and 3 only
3393(D) 1, 2, and 3
3394 --------------------------------- (C) SID is directly related to recorded detail/resolution because as SID increases, so does recorded detail/resolution (because magnification is decreased). OID is inversely related to recorded detail because as OID increases, recorded detail/resolution decreases. Motion is also inversely related to recorded detail/resolution because as motion increases, recorded detail/resolution decreases—as a result of motion blur, the greatest enemy of resolution. Therefore, of the given choices, OID and motion are inversely related to recorded detail. SID is directly related to recorded detail.
3395146. Of the following groups of exposure factors, which will produce the shortest scale of radiographic contrast?
3396(A) 500 mA, 0.040 second, 70 kV
3397(B) 100 mA, 0.100 second, 80 kV
3398(C) 200 mA, 0.025 second, 92 kV
3399(D) 700 mA, 0.014 second, 80 kV
3400 --------------------------------- (A) The single most important factor regulating radiographic contrast is kilovoltage. The lower the kilovoltage, the shorter is the scale of contrast. All the milliampere-seconds values in this problem have been adjusted for kilovoltage changes to maintain density, but just a glance at each of the kilovoltages is often a good indicator of which will produce the longest scale or shortest scale contrast.
3401148. Magnification fluoroscopy is accomplished by
34021. moving the image intensifier focal point further from the output phosphor
34032. selecting a smaller portion of the input phosphor
34043. decreasing the voltage to the electrostatic lenses
3405(A) 1 only
3406(B) 1 and 2 only
3407(C) 2 and 3 only
3408(D) 1, 2, and 3
3409 --------------------------------- (B) The input phosphor of image intensifiers is usually made of cesium iodide. For each x-ray photon absorbed by cesium iodide, approximately 5,000 light photons are emitted. As the light photons strike a photoemissive photocathode, a number of electrons are released from the photocathode and focused toward the output side of the image tube by voltage applied to the negatively charged electrostatic focusing lenses. The electrons are then accelerated through the neck of the tube where they strike the small (0.5-1 in.) output phosphor that is mounted on a flat glass support. The entire assembly is enclosed within a 2-4-mm thick vacuum glass envelope. Remember that the image on the output phosphor is minified, brighter, and inverted (electron focusing causes image inversion).
3410Input screen diameters of 5-12 in. are available. Although smaller diameter input screens improve resolution, they do not permit a large FOV, that is, viewing of large patient areas.
3411Dual- and triple-field image intensifiers are available that permit magnified viewing of fluoroscopic images. To achieve magnification, the voltage to the focusing lenses is increased and a smaller portion of the input phosphor is used, thereby resulting in a smaller FOV. Because minification gain is now decreased, the image is not as bright. The mA is automatically increased to compensate for the loss in brightness when the image intensifier is switched to magnification mode. Entrance skin exposure (ESE) can increase dramatically as the FOV decreases (i.e., as magnification increases).
3412As FOV decreases, magnification of the output screen image increases, there is less noise because increased mA provides a greater number of x-ray photons, and contrast and resolution improve. The focal point in the magnification mode is further away from the output phosphor (as a result of increased voltage applied to the focusing lenses) and therefore the output image is magnified.
3413150. Of the following groups of technical factors, which will produce the greatest radiographic density?
3414(A) 10 mAs, 74 kV, 44-in. SID
3415(B) 10 mAs, 74 kV, 36-in. SID
3416(C) 5 mAs, 85 kV, 48-in. SID
3417(D) 5 mAs, 85 kV, 40-in. SID
3418 --------------------------------- (B) If (A) and (B) are reduced to 5 mAs for consistency, the kilovoltage will increase to 85 kV in both cases, thereby balancing radiographic densities. Thus, the greatest density is determined by the shortest SID (greatest exposure rate). (Shephard, pp. 306-307)
3419In electronic imaging (CR, DR), the term brightness is used instead of density. A film image with little density would be described as a monitor digital image as having greater brightness.
3420151. Which of the following requires two exposures to evaluate focal-spot accuracy?
3421(A) Pinhole camera
3422(B) Slit camera
3423(C) Star pattern
3424(D) Bar pattern
3425 --------------------------------- (B) Focal-spot size accuracy is related to the degree of geometric blur, that is, edge gradient or penumbra. Manufacturer tolerance for new focal spots is 50%; that is, a 0.3-mm focal spot actually may be 0.45 mm. Additionally, the focal spot can increase in size as the x-ray tube ages—hence, the importance of testing newly arrived focal spots and periodic testing to monitor focal-spot changes. Focal-spot size can be measured with a pinhole camera, slit camera, or star-pattern-type resolution device. The pinhole camera is rather difficult to use accurately and requires the use of excessive tube (heat) loading. With a slit camera, two exposures are made; one measures the length of the focal spot, and the other measures the width. The star pattern, or similar resolution device, such as the bar pattern, can measure focal-spot size as a function of geometric blur and is readily adaptable in a QA program to monitor focal-spot changes over a period of time. It is recommended that focal-spot size be checked on installation of a new x-ray tube and annually thereafter.
3426152. Focusing distance is associated with which of the following?
3427(A) Computed tomography
3428(B) Chest radiography
3429(C) Magnification radiography
3430(D) Grids
3431 --------------------------------- (D) Focusing distance is the term used to specify the optimal SID used with a particular focused grid. It is usually expressed as focal range, indicating the minimum and maximum SID workable with that grid. Lesser or greater distances can result in grid cutoff. Although proper distance is important in computed tomography and chest and magnification radiography, focusing distance is unrelated to them.
3432153. The processing algorithm represents the
3433(A) pixel value distribution
3434(B) anatomical part and projection
3435(C) image grayscale
3436(D) screen speed
3437 --------------------------------- (B) The radiographer selects a processing algorithm by selecting the anatomic part and particular projection on the computer/control panel. The CR unit then matches that information with a particular lookup table (LUT)—a characteristic curve that best matches the anatomic part being imaged. The observer is able to review the image and, if desired, change its appearance (through "windowing"); doing so changes the LUT. Hence, histogram analysis and use of the appropriate LUT together function to produce predictable image quality in CR.
3438154. The relationship between the height of a grid's lead strips and the distance between them is referred to as grid
3439(A) ratio
3440(B) radius
3441(C) frequency
3442(D) focusing distance
3443 --------------------------------- (A) Grids are used in radiography to trap scattered radiation that otherwise would cause fog on the radiograph. Grid ratio is defined as the ratio of the height of the lead strips to the distance between them. Grid frequency refers to the number of lead strips per inch. Focusing distance and grid radius are terms denoting the distance range with which a focused grid may be used.
3444155. Because of the anode heel effect, the intensity of the x-ray beam is greatest along the
3445(A) path of the central ray
3446(B) anode end of the beam
3447(C) cathode end of the beam
3448(D) transverse axis of the IR
3449 --------------------------------- (C) Because the anode's focal track is beveled (angled, facing the cathode), x-ray photons can freely diverge toward the cathode end of the x-ray tube. However, the "heel" of the focal track prevents x-ray photons from diverging toward the anode end of the tube. This results in varying intensity from anode to cathode, with fewer photons at the anode end and more photons at the cathode end. The anode heel effect is most noticeable when using large IRs, short SIDs, and steep target angles.
3450156. Characteristics of high-ratio focused grids, compared with lower-ratio grids, include which of the following?
34511. They allow more positioning latitude.
34522. They are more efficient in collecting SR.
34533. They absorb more of the useful beam.
3454(A) 1 only
3455(B) 1 and 2 only
3456(C) 2 and 3 only
3457(D) 1, 2, and 3
3458 --------------------------------- (C) Two of a grid's physical characteristics that determine its degree of efficiency in the removal of scattered radiation are grid ratio (the height of the lead strips compared with the distance between them) and the number of lead strips per inch. As the lead strips are made taller or the distance between them decreases, scattered radiation is more likely to be trapped before reaching the IR. A 12:1 ratio grid will absorb more scattered radiation than an 8:1 ratio grid. An undesirable but unavoidable characteristic of grids is that they do absorb some primary/useful photons as well as scattered photons. The higher the ratio grid, the more scatter radiation the grid will clean up, but more useful photons will be absorbed as well. The higher the primary to scattered photon transmission ratio, the more desirable is the grid. Higher-ratio grids restrict positioning latitude more severely—grid centering must be more accurate (than with lower-ratio grids) to avoid grid cutoff.
3459157. Factors that can affect histogram appearance include
34601. beam restriction
34612. centering errors
34623. incorrect SID
3463(A) 1 only
3464(B) 1 and 2 only
3465(C) 2 and 3 only
3466(D) 1, 2, and 3
3467 --------------------------------- (D) In digital imaging, as in film/screen radiography, there are numerous density/brightness values that represent various tissue densities (i.e., x-ray attenuation properties), for example, bone, muscle, fat, blood-filled organs, air/gas, metal, contrast media, and pathologic processes. In CR, the CR scanner/reader recognizes these values and constructs a representative grayscale histogram of them, corresponding to the anatomic characteristics of the imaged part. Thus, all PA chest histograms are similar, all lateral chest histograms are similar, all pelvis histograms are similar, etc.
3468A histogram is a graphic representation of pixel value distribution. The histogram is an analysis and graphic representation of all the densities from the PSP screen, demonstrating the quantity of exposure, the number of pixels, and their value. Histograms are unique to each body part imaged.
3469Histogram appearance and patient dose can be affected by the radiographer's knowledge and skill using digital imaging, in addition to their degree of accuracy in positioning and centering. Collimation is exceedingly important to avoid histogram analysis errors. Lack of adequate collimation can result in signals outside the anatomic area being included in the exposure data recognition/histogram analysis. This can result in a variety of histogram analysis errors including excessively light, dark, or noisy images. Poor collimation can affect exposure level and exposure latitude; these changes are reflected in the images' informational numbers ("S number," "exposure index," etc.).
3470Other factors affecting histogram appearance, and therefore these informational numbers, include selection of the correct processing algorithm (e.g., chest vs. femur vs. cervical spine), changes in scatter, source-to-image-receptor distance (SID), object-to-image-receptor distance (OID), and collimation—in short, anything that affects scatter and/or dose.
3471159. Changes in milliampere-seconds can affect all the following except
3472(A) quantity of x-ray photons produced
3473(B) exposure rate
3474(C) optical density
3475(D) recorded detail
3476 --------------------------------- (D) Milliampere-seconds (mAs) are the product of milliamperes (mA) and exposure time (seconds). Any combinations of milliamperes and time that will produce a given milliampere-seconds value (i.e., a particular quantity of x-ray photons) will produce identical optical density. This is known as the reciprocity law. Density is a quantitative factor because it describes the amount of image blackening. The milliampere-seconds value is also a quantitative factor because it regulates x-ray-beam intensity, exposure rate, quantity, or number of x-ray photons produced (the milliampere-seconds value is the single most important technical factor associated with image density and is the factor of choice for regulating radiographic/optical density). The milliampere-seconds value is directly proportional to the intensity (i.e., exposure rate, number, and quantity) of x-ray photons produced and the resulting radiographic density. If the milliampere-seconds value is doubled, twice the exposure rate and twice the density occur. If the milliampere-seconds value is cut in half, the exposure rate and resulting density are cut in half. The milliampere-seconds value has no effect on recorded detail.
3477160. Low-kilovoltage exposure factors usually are indicated for radiographic examinations using
34781. water-soluble, iodinated media
34792. a negative contrast agent
34803. barium sulfate
3481(A) 1 only
3482(B) 1 and 2 only
3483(C) 3 only
3484(D) 1 and 3 only
3485 --------------------------------- (B) Positive contrast medium is radiopaque; negative contrast material is radioparent. Barium sulfate (radiopaque, positive contrast material) is used most frequently for examinations of the intestinal tract, and high-kilo-voltage exposure factors are used to penetrate (to see through and behind) the barium. Water-based iodinated contrast media (Conray, Amipaque) are also positive contrast agents. However, the K-edge binding energy of iodine prohibits the use of much greater than 70 kV with these materials. Higher kilovoltage values will obviate the effect of the contrast agent. Air is an example of a negative contrast agent, and high-kilovoltage factors are clearly not indicated.
3486161. Which of the following examinations might require the use of 70 kV?
34871. AP abdomen
34882. Chest radiograph
34893. Barium-filled stomach
3490(A) 1 only
3491(B) 2 only
3492(C) 1 and 2 only
3493(D) 2 and 3 only
3494 --------------------------------- (A) It is appropriate to perform an AP abdomen radiograph with lower kilovoltage because it has such low subject contrast. Abdominal tissue densities are so similar that it takes high- or short-scale contrast (using low kilovoltage) to emphasize the little difference there is between tissues. However, high-kilovoltage factors are used frequently to even out densities in anatomic parts having high tissue contrast (e.g., the chest). However, since high kilovoltage produces added scattered radiation, it generally must be used with a grid. Barium-filled structures frequently are radiographed using 120 kV or more to penetrate the barium—to see through to posterior structures
3495162. Which of the following is/are associated with magnification fluoroscopy?
34961. Increased mA
34972. Smaller portion of the input phosphor is used.
34983. Image intensifier focal point moves closer to the output phosphor.
3499(A) 1 only
3500(B) 1 and 2 only
3501(C) 2 and 3 only
3502(D) 1, 2, and 3
3503 --------------------------------- (B) The input phosphor of image intensifiers is usually made of cesium iodide. For each x-ray photon absorbed by cesium iodide, approximately 5,000 light photons are emitted. As the light photons strike a photoemissive photocathode, a number of electrons are released from the photocathode and focused toward the output side of the image tube by voltage applied to the negatively charged electrostatic focusing lenses. The electrons are then accelerated through the neck of the tube where they strike the small (0.5-1 in.) output phosphor that is mounted on a flat glass support. The entire assembly is enclosed within a 2-4-mm thick vacuum glass envelope. Remember that the image on the output phosphor is minified, brighter, and inverted (electron focusing causes image inversion).
3504Input screen diameters of 5-12 in. are available. Although smaller diameter input screens improve resolution, they do not permit a large FOV, that is, viewing of large patient areas.
3505Dual- and triple-field image intensifiers are available that permit magnified viewing of fluoroscopic images. To achieve magnification, the voltage to the focusing lenses is increased and a smaller portion of the input phosphor is used, thereby resulting in a smaller FOV. Because minification gain is now decreased, the image is not as bright. The mA is automatically increased to compensate for the loss in brightness when the image intensifier is switched to magnification mode. Entrance skin exposure (ESE) can increase dramatically as the FOV decreases (i.e., as magnification increases).
3506As FOV decreases, magnification of the output screen image increases, there is less noise because increased mA provides a greater number of x-ray photons, and contrast and resolution improve. The focal point in the magnification mode is further away from the output phosphor (as a result of increased voltage applied to the focusing lenses) and therefore the output image is magnified.
3507163. A lateral projection of the lumbar spine was made using 200 mA, 1-second exposure, and 90 kV. If the exposure factors were changed to 200 mA, 0.5 second, and 104 kV, there would be an obvious change in which of the following?
35081. Radiographic density
35092. Scale of radiographic contrast
35103. Distortion
3511(A) 1 only
3512(B) 2 only
3513(C) 2 and 3 only
3514(D) 1, 2, and 3
3515 --------------------------------- (B) The original milliampere-seconds value (regulating radiographic density) was 200. The original kilovoltage (regulating radiographic contrast) was 90. The milliampere-seconds value was cut in half, to 100, causing a decrease in density. The kilovoltage was increased (by 15%) to compensate for the density loss and thereby increase the scale of contrast.
3516164. A decrease in kilovoltage will result in
3517(A) a decrease in optical density
3518(B) a decrease in contrast
3519(C) a decrease in recorded detail
3520(D) a decrease in image resolution
3521 --------------------------------- (A) As kilovoltage is increased, more electrons are driven to the anode with greater speed and energy. More high-energy electrons will result in production of more high-energy x-rays. Thus, kilovoltage affects both quantity and quality (energy) of the x-ray beam. However, although kilovoltage and radiographic density are directly related, they are not directly proportional; that is, twice the radiographic density does not result from doubling the kilovoltage. With respect to the effect of kilovoltage on image density, if it is desired to double the radiographic density yet impossible to adjust the milliampere-seconds, a similar effect can be achieved by increasing the kilovoltage by 15%. Conversely, the density may be cut in half by decreasing the kilovoltage by 15%. Therefore, a decrease in kilovoltage will produce fewer x-ray photons, resulting in decreased density. Additionally, a decrease in kilovoltage will produce fewer shades of gray, that is, a shorter-scale, or higher/increased, contrast. Kilovoltage is unrelated to recorded detail and resolution.
3522165. Brightness and contrast resolution in digital imaging can be influenced by
35231. window level (WL)
35242. window width (WW)
35253. look-up table (LUT)
3526(A) 1 only
3527(B) 1 and 2 only
3528(C) 2 and 3 only
3529(D) 1, 2, and 3
3530 --------------------------------- (D) The radiographer selects a processing algorithm by selecting the anatomic part and particular projection on the computer/control panel. The CR unit then matches that information with a particular lookup table (LUT)—a characteristic curve that best matches the anatomic part being imaged. The observer is able to review the image and, if desired, change its appearance (through "windowing"); doing so changes the LUT. Histogram analysis and use of the appropriate LUT together function to produce predictable image quality in CR. Additionally, the radiographer can manipulate, that is, change and enhance, the digital image displayed on the display monitor through postprocessing. One way to alter image contrast and/or brightness is through windowing. The term windowing refers to some change made to window width and/or window level, that is, a change in the LUT. Change in window width affects change in the number of gray shades, that is, image contrast. Change in window level affects change in the image brightness, that is, density. Therefore, windowing and other postprocessing mechanisms permit the radiographer to affect changes in the image and produce "special effects," such as contrast enhancement, edge enhancement, image stitching.
3531166. What feature is used to display RIS information on current patients?
3532(A) HIS
3533(B) Modality work list
3534(C) PACS
3535(D) DICOM
3536 --------------------------------- (B) Patient demographic and examination information originates from the hospital/facility HIS, where it is obtained when the patient is initially registered. That information is available or retrievable when the patient is scheduled, or arrives, for imaging services. Typical patient information includes name, DOB or age, sex, ID number, accession number, examination being performed, date and time of examination.
3537Additional information may be available on the examination requisition; more information is usually entered by the technologist at the time of the examination.
3538A feature that is useful in sorting examinations and decreasing (but not eliminating) errors is the Modality Work List (MWL). The MWL "brings up" existing RIS information, that is, the examinations scheduled for each imaging area—for example, x-ray, CT, MR, mammography, ultrasound, etc. The technologist selects the correct patient, which includes that patient's particular demographics, from the particular modality work list.
3539It is essential that the technologist is attentive to detail and accuracy when entering patient information; errors in patient demographics entry, and entry duplication, must be avoided.
3540PACS is used by health care facilities to economically store, archive, exchange, transmit digital images from multiple imaging modalities; it replaces the need to manually file, retrieve, and transport film and film jackets.
3541RIS and HIS can be integrated with PACS for electronic health information storage. The purpose of HIS is to manage health care information and documents electronically, and to ensure data security and availability. RIS is a system for tracking radiological and imaging procedures. RIS is used for patient registration and scheduling, radiology workflow management, reporting and printout, manipulation and distribution and tracking of patient data, and billing. RIS complements HIS and is critical to competent workflow to radiologic facilities.
3542167. A decrease from 200 to 100 mA will result in a decrease in which of the following?
35431. Wavelength
35442. Exposure rate
35453. Beam intensity
3546(A) 1 only
3547(B) 1 and 2 only
3548(C) 2 and 3 only
3549(D) 1, 2, and 3
3550 --------------------------------- (C) Technical factors can be expressed in terms of milliampere-seconds rather than milliamperes and time. The milliampere-seconds value is a quantitative factor because it regulates x-ray-beam intensity, exposure rate, quantity, or number of x-ray photons produced (the milliampere-seconds value is the single most important technical factor associated with image density and is the factor of choice for regulating radiographic/optical density). The milliampere-seconds value is directly proportional to the intensity (i.e., exposure rate, number, and quantity) of x-ray photons produced and the resulting radiographic density. If the milliampere-seconds value is doubled, twice the exposure rate and twice the density occur. If the milliampere-seconds value is cut in half, the exposure rate and resulting density are cut in half. Kilovoltage is the qualitative exposure factor—it determines beam quality by regulating photon energy (i.e., wavelength).
3551169. The effect described as differential absorption is
35521. responsible for radiographic contrast
35532. a result of attenuating characteristics of tissue
35543. minimized by the use of a high peak kilovoltage
3555(A) 1 only
3556(B) 1 and 2 only
3557(C) 1 and 3 only
3558(D) 1, 2, and 3
3559 --------------------------------- (D) Differential absorption refers to the x-ray absorption characteristics of neighboring anatomic structures. The radiographic representation of these structures is referred to as radiographic contrast; it may be enhanced with high-contrast technical factors, especially using low kilovoltage levels. At low-kilovoltage levels, the photoelectric effect predominates.
3560170. A satisfactory radiograph of the abdomen was made at a 38-in. SID using 400 mA, 60-ms exposure, and 80 kV. If the distance is changed to 42 in., what new exposure time would be required?
3561(A) 25 ms
3562(B) 50 ms
3563(C) 73 ms
3564(D) 93 ms
3565 --------------------------------- (C) According to the inverse-square law of radiation, as the distance between the radiation source and the IR decreases, the exposure rate increases. Therefore, a decrease in technical factors is indicated. The density-maintenance formula is used to determine new milliampere-seconds values when changing distance:
3566
3567
3568Thus, mAs at 42-in. SID. Then, to determine the new exposure time (),
3569
3570
3571Thus, second (73 ms) at 400 mA.
3572171. Which of the following is (are) associated with subject contrast?
35731. Patient thickness
35742. Tissue density
35753. Kilovoltage
3576(A) 1 only
3577(B) 1 and 2 only
3578(C) 1 and 3 only
3579(D) 1, 2, and 3
3580 --------------------------------- (D) Radiographic contrast is the sum of film emulsion contrast and subject contrast. Subject contrast has by far the greatest influence on radiographic contrast. Several factors influence subject contrast, each as a result of beam-attenuation differences in the irradiated tissues. As patient thickness and tissue density increase, attenuation increases, and subject contrast is increased. As kilovoltage increases, higher-energy photons are produced, beam attenuation is decreased, and subject contrast decreases.
3581172. Typical patient demographic and examination information include(s)
35821. type of examination
35832. accession number
35843. date and time of examination
3585(A) 1 only
3586(B) 1 and 2 only
3587(C) 2 and 3 only
3588(D) 1, 2, and 3
3589 --------------------------------- (D) Patient demographic and examination information originates from the hospital/facility HIS, where it is obtained when the patient is initially registered. That information is available or retrievable when the patient is scheduled, or arrives, for imaging services. Typical patient information includes name, DOB or age, sex, ID number, accession number, examination being performed, date and time of examination.
3590Additional information may be available on the examination requisition; more information is usually entered by the technologist at the time of the examination.
3591A feature that is useful in sorting examinations and decreasing (but not eliminating) errors is the Modality Work List (MWL). The MWL "brings up" existing RIS information, that is, the examinations scheduled for each imaging area—for example, x-ray, CT, MR, mammography, ultrasound, etc. The technologist selects the correct patient, which includes that patient's particular demographics, from the particular modality work list.
3592It is essential that the technologist is attentive to detail and accuracy when entering patient information; errors in patient demographics entry, and entry duplication, must be avoided.
3593173. For which of the following examinations might the use of a grid not be necessary in an adult patient?
3594(A) Hip
3595(B) Knee
3596(C) Abdomen
3597(D) Lumbar spine
3598 --------------------------------- (B) The abdomen is a thick structure that contains many structures of similar density, and thus it requires increased exposure and a grid to absorb scattered radiation. The lumbar spine and hip are also dense structures requiring increased exposure and use of a grid. The knee, however, is frequently small enough to be radiographed without a grid. The general rule is that structures measuring more than 10 cm should be radiographed with a grid.
3599174. The quantity of scattered radiation reaching the IR can be reduced through the use of
36001. a fast imaging system
36012. an air gap
36023. a stationary grid
3603(A) 1 and 2 only
3604(B) 1 and 3 only
3605(C) 2 and 3 only
3606(D) 1, 2, and 3
3607 --------------------------------- (C) Scattered radiation adds unwanted degrading densities to the x-ray image. The single most important way to reduce the production of scattered radiation is to collimate. Although collimation, optimal kilovoltage, and compression can be used, a large amount of scattered radiation is still generated within the part being imaged, and because it adds unwanted non-information-carrying densities, it can have a severely degrading effect on image quality. A grid is a device interposed between the patient and IR that functions to absorb a large percentage of scattered radiation before it reaches the IR. It is constructed of alternating strips of lead foil and radiolucent filler material. X-ray photons traveling in the same direction as the primary beam pass between the lead strips. X-ray photons, having undergone interactions within the body and deviated in various directions, are absorbed by the lead strips; this is referred to as cleanup of scattered radiation. An air gap introduced between the object and IR can have an effect similar to that of a grid. As energetic scattered radiation emerges from the body, it continues to travel in its divergent fashion and much of the time will bypass the IR. It is usually necessary to increase the SID to reduce magnification caused by increased OID. Imaging system speed is unrelated to scattered radiation.
3608175. Why is a very short exposure time essential in chest radiography?
3609(A) To avoid excessive focal-spot blur
3610(B) To maintain short-scale contrast
3611(C) To minimize involuntary motion
3612(D) To minimize patient discomfort
3613 --------------------------------- (C) Radiographers usually are able to stop voluntary motion using suspended respiration, careful instruction, and immobilization. However, involuntary motion also must be considered. To have a "stop action" effect on the heart when radiographing the chest, it is essential to use a short exposure time.
3614177. Beam attenuation characteristics, or density values, in CT are expressed as
36151. Hounsfield units
36162. CT numbers
36173. heat units
3618(A) 1 only
3619(B) 1 and 2 only
3620(C) 2 and 3 only
3621(D) 1, 2, and 3
3622 --------------------------------- (B) Sir Godfrey Newbold Hounsfield created the first CT unit, describing the reconstruction of data taken from multiple projection angles. Alan MacLeod Cormack worked with the complex mathematical algorithms required for image reconstruction. Their first commercial CT head scanner was available in 1971. In 1979, Hounsfield and Cormack shared the Nobel Prize in Medicine for their historic work with this new imaging science.
3623To express the beam attenuation characteristics of various tissues, the Hounsfield unit (HU) is used. HUs can also be referred to as CT numbers or density values. Godfrey Hounsfield assigned a value of 0 to distilled water, a value of +1,000 to dense osseous tissue, and a value of -1,000 to air. There is a direct relationship between the HU and tissue attenuation coefficient. The greater the attenuation coefficient of the particular tissue, the higher the HU value. One HU represents a 0.1% difference between the particular tissue attenuation characteristics and that of distilled water. HU value accuracy can be affected by equipment calibration, volume averaging, and image artifacts.
3624178. An exposure was made at a 36-in. SID using 300 mA, a 30-ms exposure, and 80 kV and an 8:1 grid. It is desired to repeat the radiograph using a 40-in. SID and 70 kV. With all other factors remaining constant, what new exposure time will be required?
3625(A) 0.03 second
3626(B) 0.07 second
3627(C) 0.14 second
3628(D) 0.36 second
3629 --------------------------------- (B) A review of the problem reveals that three changes are being made: an increase in SID, a decrease in kV, and a change in exposure time (to be considered last). The original mAs value was 9. The decrease in kV requires us to double the mAs in order to maintain sufficient exposure. Now, we must deal with the distance change. Using the density-maintenance formula (and remembering that 18 is now the old milliampere-seconds value), we find that the required new milliampere-seconds value at 42 in. is 22.
3630
3631
3632Thus, mAs at 40-in. SID. Because milliamperage is unchanged, we must determine the exposure time that, when used with 300 mA, will yield 22 mAs.
3633179. Which of the following is (are) characteristic(s) of a 5:1 grid?
36341. It allows some positioning latitude.
36352. It is used with high-kilovoltage exposures.
36363. It absorbs a high percentage of scattered radiation.
3637(A) 1 only
3638(B) 1 and 3 only
3639(C) 2 and 3 only
3640(D) 1, 2, and 3
3641 --------------------------------- (A) Low-ratio grids, such as 5:1, 6:1, and 8:1, are used with moderate-kilovolt techniques and are not recommended for use beyond 85 kV. They are not able to clean up the amount of scatter produced at high kilovoltages, but their low ratio permits more positioning latitude than high-ratio grids. High-kilovoltage exposures produce large amounts of scattered radiation, and therefore, high-ratio grids are used in an effort to trap more of this scattered radiation. However, accurate centering and positioning become more critical to avoid grid cutoff.
3642180. How is SID related to exposure rate and image density?
3643(A) As SID increases, exposure rate increases and image density increases.
3644(B) As SID increases, exposure rate increases and image density decreases.
3645(C) As SID increases, exposure rate decreases and image density increases.
3646(D) As SID increases, exposure rate decreases and image density decreases.
3647 --------------------------------- (D) According to the inverse-square law of radiation, the intensity or exposure rate of radiation is inversely proportional to the square of the distance from its source. Thus, as distance from the source of radiation increases, exposure rate decreases. Because exposure rate and image density are directly proportional, if the exposure rate of a beam directed to an IR is decreased, the resulting image density would be decreased proportionately.
3648181. An x-ray exposure of a particular part is made and restricted to a 14 × 17 in. field size. The same exposure is repeated, but the x-ray beam is restricted to a 4 × 4 in. field. Compared with the first image, the second image will demonstrate
36491. more contrast
36502. higher contrast
36513. more density
3652(A) 1 only
3653(B) 1 and 2 only
3654(C) 3 only
3655(D) 2 and 3 only
3656 --------------------------------- (B) Less scattered radiation is generated within a part as the kilovoltage is decreased, as the size of the field is decreased, and as the thickness and density of tissue decrease. As the quantity of scattered radiation decreases from any of these sources, the higher/greater will be the contrast and the less is the overall density (greater brightness) of the resulting image.
3657182. In digital imaging, TFT DEL size is related to
3658(A) contrast
3659(B) brightness
3660(C) spatial resolution
3661(D) plate size
3662 --------------------------------- (C) Factors influencing recorded detail in digital imaging are very much the same as those factors affecting recorded detail in analog imaging, that is, motion, geometric factors (focal spot size, OID, and SID), and spatial resolution. The spatial resolution of direct digital systems is fixed and is related to the detector element (DEL) size of the thin film transistor (TFT). The smaller the TFT DEL size, the better the spatial resolution. DEL size of 100 microns provides a spatial resolution of about 5 lp/mm (available only in some digital mammography systems). DEL size of 200 microns provides a spatial resolution of about 2.5 lp/mm (general radiography)—lower than that achieved with 400 speed intensifying screen system. A 100 speed intensifying screen system offers a spatial resolution of about 10 lp/mm—significantly greater than, and currently unachievable in, digital imaging. Spatial resolution in digital imaging is fixed, but it is very important that radiographers are alert to the opportunity they have to utilize and control the remaining recorded detail factors (motion and geometric factors).
3663183. Which of the following pathologic conditions would require an increase in exposure factors?
3664(A) Pneumoperitoneum
3665(B) Obstructed bowel
3666(C) Renal colic
3667(D) Ascites
3668 --------------------------------- (D) Because pneumoperitoneum is an abnormal accumulation of air or gas in the peritoneal cavity, it would require a decrease in exposure factors. Obstructed bowel usually involves distended, air- or gas-filled bowel loops, again requiring a decrease in exposure factors. With ascites, there is an abnormal accumulation of fluid in the abdominal cavity, necessitating an increase in exposure factors. Renal colic is the pain associated with the passage of renal calculi; no change from the normal exposure factors is usually required.
3669184. Factors that determine recorded detail in digital imaging include
36701. focal spot size
36712. SID
36723. DEL size
3673(A) 1 only
3674(B) 1 and 2 only
3675(C) 2 and 3 only
3676(D) 1, 2, and 3
3677 --------------------------------- (D) Factors influencing recorded detail in digital imaging are very much the same as those factors affecting recorded detail in analog imaging, that is, motion, geometric factors (focal spot size, OID, and SID), and spatial resolution. In analog imaging, spatial resolution is related to the speed of the imaging system (intensifying screen speed) and is significantly better than digital imaging resolution. The spatial resolution of direct digital systems, however, is fixed and is related to the detector element (DEL) size of the thin film transistor (TFT). The smaller the TFT DEL size, the better the spatial resolution. DEL size of 100 microns provides a spatial resolution of about 5 lp/mm (available only in some digital mammography systems). DEL size of 200 microns provides a spatial resolution of about 2.5 lp/mm (general radiography)—lower than that achieved with 400 speed intensifying screen system. A 100 speed intensifying screen system offers a spatial resolution of about 10 lp/mm—significantly greater than, and currently unachievable in, digital imaging. Spatial resolution in digital imaging is fixed, but it is very important that radiographers are alert to the opportunity they have to utilize and control the remaining recorded detail factors (motion and geometric factors).
3678185. The photostimulable phosphor (PSP) plates used in CR are constructed in layers that include
36791. light shield layer
36802. support layer
36813. electroconductive layer
3682(A) 1 only
3683(B) 1 and 2 only
3684(C) 2 and 3 only
3685(D) 1, 2, and 3
3686 --------------------------------- (D) The PSP plate within the CR image plate has several layers. Its uppermost layer is a protective coat for the phosphor layer below. This layer affords durability and must be translucent to allow passage of photostimulable luminescent light. The phosphor layer is the "active" layer that responds to the x-ray photons that reach it. Under the phosphor layer is the electroconductive layer that serves to facilitate transportation through the scanner/reader and prevent image artifacts resulting from static electricity. Below the electroconductive layer is the plate support layer. Below the support layer is a light-shield layer that serves to prevent light from erasing image plate data or from approaching through the rear protective layer. Behind the light-shield layer is the rear protective layer of the PSP plate.
3687186. A QA program serves to
36881. keep patient dose to a minimum
36892. keep radiographic quality consistent
36903. ensure equipment efficiency
3691(A) 1 only
3692(B) 1 and 2 only
3693(C) 1 and 3 only
3694(D) 1, 2, and 3
3695 --------------------------------- (D) A QA program includes regular overseeing of all components of the imaging system—equipment calibration, film and cassettes, processor, x-ray equipment, and so on. With regular maintenance, testing, and repairs, equipment should operate efficiently and consistently. In turn, radiographic quality will be consistent, and repeat exposures will be minimized, thereby reducing patient exposure.
3696187. The purpose of the electroconductive layer of a CR PSP plate is to
3697(A) provide support to the PSP layer
3698(B) provide mechanical strength
3699(C) facilitate transportation through the scanner/reader
3700(D) provide better resolution
3701 --------------------------------- (C) The PSP plate within the CR cassette/IP has several layers. Its uppermost layer is a protective coat for the phosphor layer below. This layer affords durability and must be translucent to allow passage of photostimulable luminescent light. The phosphor layer is the "active" layer that responds to the x-ray photons that reach it. Under the phosphor layer is the electroconductive layer that serves to facilitate transportation through the scanner/reader and prevent image artifacts resulting from static electricity. Below the electroconductive layer is the plate support layer. Below the support layer is a light-shield layer that serves to prevent light from erasing image plate data or from approaching through the rear protective layer. Behind the light-shield layer is the rear protective layer of the PSP plate.
3702188. Any images obtained using dual x-ray absorptiometry (DXA) bone densitometry
37031. are used to evaluate accuracy of the region of interest (ROI)
37042. are used as evaluation for various bone/joint disorders
37053. reflect the similar attenuation properties of soft tissue and bone
3706(A) 1 only
3707(B) 1 and 2 only
3708(C) 1 and 3 only
3709(D) 1, 2, and 3
3710 --------------------------------- (A) DXA imaging is used to evaluate BMD. It is the most widely used method of bone densitometry—it is low-dose, precise, and uncomplicated to use/perform. DXA uses two photon energies—one for soft tissue and one for bone. Since bone is denser and attenuates x-ray photons more readily, their attenuation is calculated to represent the degree of bone density. Soft tissue attenuation information is not used to measure bone density. Any images obtained in DXA/bone densitometry are strictly to evaluate the accuracy of the region of interest (ROI); they are not used for further diagnostic purposes—additional diagnostic examinations are done for any required further evaluation. Bone densitometry/DXA can be used to evaluate bone mineral content of the body or part of it, to diagnose osteoporosis, or to evaluate the effectiveness of treatments for osteoporosis.
3711189. Foreshortening of an anatomic structure means that
3712(A) it is projected on the IR smaller than its actual size
3713(B) its image is more lengthened than its actual size
3714(C) it is accompanied by geometric blur
3715(D) it is significantly magnified
3716 --------------------------------- (A) If a structure of a given length is not positioned parallel to the recording medium (PSP or film), it will be projected smaller than its actual size (foreshortened). An example of this can be a lateral projection of the third digit. If the finger is positioned so as to be parallel to the IR, no distortion will occur. If, however, the finger is positioned so that its distal portion rests on the cassette while its proximal portion remains a distance from the IR, foreshortening will occur.
3717190. To produce a just perceptible increase in radiographic density, the radiographer must increase the
3718(A) mAs by 30%
3719(B) mAs by 15%
3720(C) kV by 15%
3721(D) kV by 30%
3722 --------------------------------- (A) If a radiograph lacks sufficient blackening, an increase in milliampere-seconds is required. The milliampere-seconds value regulates the number of x-ray photons produced at the target. An increase or decrease in milliampere-seconds of at least 30% is necessary to produce a perceptible effect. Increasing the kilovoltage by 15% will have about the same effect as doubling the milliampere-seconds.
3723191. A radiograph made using 300 mA, 0.1 second, and 75 kV exhibits motion unsharpness but otherwise satisfactory technical quality. The radiograph will be repeated using a shorter exposure time. Using 86 kV and 400 mA, what should be the new exposure time?
3724(A) 25 ms
3725(B) 37 ms
3726(C) 50 ms
3727(D) 75 ms
3728 --------------------------------- (B) The milliampere-seconds (mAs) formula is milliamperage × time = mAs. With two of the factors known, the third can be determined. To find the milliampere-seconds value that was used originally, substitute the known values:
3729
3730
3731We have increased the kilovoltage to 86 kV, an increase of 15%, which has an effect similar to that of doubling the milliampere-seconds. Therefore, only 15 mAs is now required as a result of the kilovoltage increase:
3732
3733
3734Thus, -s exposure = 37.5 ms.
3735193. X-ray tubes used in CT differ from those used in x-ray, in that CT x-ray tubes must
37361. have a very high short-exposure rating
37372. be capable of tolerating several million heat units
37383. have a small focal spot for optimal resolution
3739(A) 1 only
3740(B) 1 and 2 only
3741(C) 2 and 3 only
3742(D) 1, 2, and 3
3743 --------------------------------- (D) A CT imaging system has three component parts—a gantry, a computer, and an operating console. The gantry component includes an x-ray tube, a detector array, a high-voltage generator, a collimator assembly, and a patient couch with its motorized mechanism. While the CT x-ray tube is similar to direct-projection x-ray tubes, it has several special requirements. The CT x-ray tube must have a very high short-exposure rating and must be capable of tolerating several million heat units while still having a small focal spot for optimal resolution. To help tolerate the very high production of heat units, the anode must be capable of high-speed rotation. The x-ray tube produces a pulsed x-ray beam (1-5 ms) using up to about 1,000 mA.
3744195. Exposure-type artifacts include
37451. double exposure
37462. motion
37473. image fading
3748(A) 1 only
3749(B) 1 and 2 only
3750(C) 2 and 3 only
3751(D) 1, 2, and 3
3752 --------------------------------- (B) Artifacts can be a result of exposure, handling, and storage, or processing. Exposure artifacts include motion, double exposure, and patient clothing/jewelry—the effects of these are seen as a result of the exposure. Handling and storage artifacts include fogged PSP, image fading, upside down IP, damaged PSP—all these occur as a result of improper use or storage. Processing artifacts occur while the PSP is in the scanner/reader and include skipped scan lines, laser jitter, etc.
3753196. When involuntary motion must be considered, the exposure time may be cut in half if the kilovoltage is
3754(A) doubled
3755(B) increased by 15%
3756(C) increased by 25%
3757(D) increased by 35%
3758 --------------------------------- (B) If the exposure time is cut in half, one normally would double the milliamperage to maintain the same milliampere-seconds value and, consequently, the same radiographic density. However, increasing the kilovoltage by 15% has a similar effect. For example, if the original kilovoltage were 85 kV, 15% of this is 13, and therefore, the new kilovoltage would be 98 kV. The same percentage value would be used to cut the radiographic density in half (reduce kilovoltage by 15%).
3759197. Which of the following groups of exposure factors would be most effective in eliminating prominent pulmonary vascular markings in the RAO position of the sternum?
3760(A) 500 mA, 1/30 s, 70 kV
3761(B) 200 mA, 0.04 second, 80 kV
3762(C) 300 mA, 1/10 s, 80 kV
3763(D) 25 mA, 7/10 s, 70 kV
3764 --------------------------------- (D) In the RAO position, the sternum must be visualized through the thorax and heart. Prominent pulmonary vascular markings can hinder good visualization. A method frequently used to overcome this problem is to use a milliampere-seconds value with a long exposure time. The patient is permitted to breathe normally during the (extended) exposure and by so doing blurs out the prominent vascularities.
3765198. An exposure was made of a part using 300 mA and 0.06 second with a 200-speed film-screen combination. An additional radiograph is requested using a 400-speed system to reduce motion unsharpness. Using 400 mA, all other factors remaining constant, what should be the new exposure time?
3766(A) 5 ms
3767(B) 11 ms
3768(C) 22 ms
3769(D) 44 ms
3770 --------------------------------- (C) High-speed imaging systems are valuable for reducing patient exposure and patient motion. However, some detail will be sacrificed, and quantum mottle can cause further image impairment. In general, doubling the film-screen speed doubles the radiographic density, thereby requiring that the milliampere-seconds value be halved to maintain the original radiographic density. Changing from 200 to 400 screens requires halving the milliampere-seconds value to 9 mAs. The new exposure time, using 400 mA, is . Thus, -s exposure using 400 mA and 400-speed screens .
3771200. HVL is affected by the amount of
37721. kVp
37732. beam filtration
37743. tissue density
3775(A) 1 only
3776(B) 1 and 2 only
3777(C) 2 and 3 only
3778(D) 1, 2, and 3
3779 --------------------------------- (B) Manufacturers of x-ray equipment must follow guidelines that state maximum x-ray output at specific distances, total quantities of filtration, positive beam limitation, and other guidelines. Radiographers must practice safe principles of operation; preventive maintenance and quality control (QC) checks must be performed at specific intervals to ensure continued safe equipment performance. Radiologic QC involves monitoring and regulating the variables associated with image production and patient care.
3780HVL testing provides beam quality information that is different from that obtained from kV testing. HVL is defined as the thickness of any absorber that will reduce x-ray beam intensity to one-half its original value. It is determined by measuring the beam intensity without an absorber and then recording the intensity as successive millimeters of aluminum are added to the radiation field. It is influenced by the type of rectification, total filtration, and kV. An x-ray tube HVL should remain almost constant. If HVL decreases, it is an indication of a decrease in the actual kV. If the HVL increases, it indicates the deposition of vaporized tungsten on the inner surface of the glass envelope (as a result of tube aging) or an increase in the actual kV.
3781201. The attenuation of x-ray photons is not influenced by
37821. pathology
37832. structure atomic number
37843. photon quantity
3785(A) 1 only
3786(B) 3 only
3787(C) 2 and 3 only
3788(D) 1, 2, and 3
3789 --------------------------------- (B) Attenuation (decreased intensity through scattering or absorption) of the x-ray beam is a result of its original energy and its interactions with different types and thicknesses of tissue. The greater the original energy/quality (the higher the kilovoltage) of the incident beam, the less is the attenuation. The greater the effective atomic number of the tissues (tissue type and pathology determine absorbing properties), the greater is the beam attenuation. The greater the volume of tissue (subject density and thickness), the greater is the beam attenuation.
3790202. If, upon QC testing, the HVL of the x-ray beam produced by a particular x-ray tube increases, it is an indication of
37911. vaporized tungsten deposited on the inner surface of the glass envelope
37922. an increase in the kilovoltage being produced by the tube
37933. a decrease in the kilovoltage being produced by the tube
3794(A) 1 only
3795(B) 1 and 2 only
3796(C) 2 and 3 only
3797(D) 1, 2, and 3
3798 --------------------------------- (B) Manufacturers of x-ray equipment must follow guidelines that state maximum x-ray output at specific distances, total quantities of filtration, positive beam limitation, and other guidelines. Radiographers must practice safe principles of operation; preventive maintenance and quality control (QC) checks must be performed at specific intervals to ensure continued safe equipment performance. Radiologic QC involves monitoring and regulating the variables associated with image production and patient care.
3799HVL testing provides beam quality information that is different from that obtained from kV testing. HVL is defined as the thickness of any absorber that will reduce x-ray beam intensity to one-half its original value. It is determined by measuring the beam intensity without an absorber and then recording the intensity as successive millimeters of aluminum are added to the radiation field. It is influenced by the type of rectification, total filtration, and kV. An x-ray tube HVL should remain almost constant. If HVL decreases, it is an indication of a decrease in the actual kV. If the HVL increases, it indicates the deposition of vaporized tungsten on the inner surface of the glass envelope (as a result of tube aging) or an increase in the actual kV.
3800203. A compensating filter is used to
3801(A) absorb the harmful photons that contribute only to patient dose
3802(B) even out widely differing tissue densities
3803(C) eliminate much of the scattered radiation
3804(D) improve fluoroscopy
3805 --------------------------------- (B) A compensating filter is used to make up for widely differing tissue densities. For example, it is difficult to obtain a satisfactory image of the mediastinum and lungs simultaneously without the use of a compensating filter to "even out" the densities. With this device, the chest is radiographed using mediastinal factors, and a trough-shaped filter (thicker laterally) is used to absorb excess photons that would overexpose the lungs. The middle portion of the filter lets the photons pass to the mediastinum almost unimpeded. Filters that absorb the photons contributing to skin dose are inherent and added filters. Compensating filtration is unrelated to elimination of scattered radiation or fluoroscopy.
3806204. Boxes of film stored in too warm an area may be subject to
3807(A) static marks
3808(B) film fog
3809(C) high contrast
3810(D) loss of density
3811 --------------------------------- (B) X-ray film emulsion is sensitive and requires proper handling and storage. It should be stored in a cool (40-60°F), dry (40-60% humidity) place. Exposure to excessive temperatures or humidity can lead to film fog and loss of contrast. Static marks are a result of low humidity.
3812205. Which of the following will influence recorded detail?
38131. Dynamic range
38142. Part motion
38153. Focal spot
3816(A) 1 and 2 only
3817(B) 1 and 3 only
3818(C) 2 and 3 only
3819(D) 1, 2, and 3
3820 --------------------------------- (C) Motion is the greatest enemy of resolution. While everything else may be perfect, if motion is introduced, resolution is lost. Focal spot blur is related to focal spot size; smaller focal spots produce less blur and thus better recorded detail/resolution. Pixel depth is directly related to shades of gray—called dynamic range—and is measured in bits. The greater the number of bits, the more shades of gray. Dynamic range is not related to resolution.
3821206. Which interaction is responsible for producing the most x-ray photons at the x-ray tube target?
3822(A) Bremsstrahlung
3823(B) Characteristic
3824(C) Photoelectric
3825(D) Compton
3826 --------------------------------- (A) Diagnostic x-rays are produced within the x-ray tube when high-speed electrons are rapidly decelerated upon encountering the tungsten atoms of the anode/target. The source of electrons is the heated cathode filament; they are driven across to the anode focal spot when thousands of volts (kV) are applied. When the high-speed electrons are suddenly stopped at the focal spot, their kinetic energy is converted to x-ray photon energy. This happens in two ways:
3827 
3828Bremsstrahlung ("Brems") or "braking" radiation: A high-speed electron, passing near or through a tungsten atom, is attracted and "braked" (i.e., slowed down) by the positively charged nucleus and deflected from its course with a loss of energy. This energy loss is given up in the form of an x-ray photon. The electron might not give up all its kinetic energy in one interaction; it can go on to have several more interactions deeper in the anode, each time producing an x-ray photon having less and less energy. This is one reason the x-ray beam is polyenergetic, that is, has a spectrum of energies. Brems radiation comprises 70-90% of the x-ray beam.
3829Characteristic radiation: In this case, a high-speed electron encounters a tungsten atom within the anode and ejects a K shell electron, leaving a vacancy in that shell. An electron from the adjacent L shell moves to the K shell to fill its vacancy and in doing so emits a K characteristic ray. The energy of the characteristic ray is equal to the difference in energy between the K and L shell energy levels. Characteristic radiation comprises 10-30% of the x-ray beam.
3830Photoelectric effect and Compton scatter are interactions that occur between x-ray photons and matter.
3831207. Which of the following terms is used to describe unsharp edges of tiny radiographic details?
3832(A) Diffusion
3833(B) Mottle
3834(C) Blur
3835(D) Umbra
3836 --------------------------------- (C) Recorded detail is evaluated by how sharply tiny anatomic details are imaged on the radiograph. The area of blurriness that may be associated with small image details is termed geometric blur. The blurriness can be produced by using a large focal spot or by diffused fluorescent light from intensifying screens. The image proper (i.e., without blur) is termed the umbra. Mottle is a grainy appearance caused by fast imaging systems.
3837208. Which of the following is (are) classified as rare earth phosphors?
38381. Lanthanum oxybromide
38392. Gadolinium oxysulfide
38403. Cesium iodide
3841(A) 1 only
3842(B) 1 and 2 only
3843(C) 2 and 3 only
3844(D) 1, 2, and 3
3845 --------------------------------- (B) Rare earth phosphors have a greater conversion efficiency than do other phosphors. Lanthanum oxybromide is a blue-emitting rare earth phosphor, and gadolinium oxysulfide is a green-emitting rare earth phosphor. Cesium iodide is the phosphor used on the input screen of image intensifiers; it is not a rare earth phosphor.
3846210. As grid ratio is decreased,
3847(A) the scale of contrast becomes longer
3848(B) the scale of contrast becomes shorter
3849(C) radiographic density decreases
3850(D) radiographic distortion decreases
3851 --------------------------------- (A) Because lead content decreases when grid ratio decreases, a smaller amount of scattered radiation is trapped before reaching the IR. More grays, therefore, are recorded, and a longer scale of contrast results. Radiographic density would increase with a decrease in grid ratio. Grid ratio is unrelated to distortion.
3852211. X-ray film emulsion is most sensitive to safelight fog
3853(A) before exposure and development
3854(B) after exposure
3855(C) during development
3856(D) at low humidity
3857 --------------------------------- (B) X-ray film emulsion becomes more sensitive to safelight fog following exposure to fluorescent light from intensifying screens. Care must be taken not to leave exposed film on the darkroom workbench for any length of time because its sensitivity to safelight fog is now greatly heightened.
3858212. Which of the following focal-spot sizes should be employed for magnification radiography?
3859(A) 0.2 mm
3860(B) 0.6 mm
3861(C) 1.2 mm
3862(D) 2.0 mm
3863 --------------------------------- (A) Proper use of focal spot size is of paramount importance in magnification radiography. A magnified image that is diagnostic can be obtained only by using a fractional focal spot of 0.3 mm or smaller. The amount of blur or geometric unsharpness produced by focal spots that are larger in size render the radiograph undiagnostic.
3864213. If a 6-in. OID is introduced during a particular radiographic examination, what change in SID will be necessary to overcome objectionable magnification?
3865(A) The SID must be increased by 6 in..
3866(B) The SID must be increased by 18 in..
3867(C) The SID must be decreased by 6 in..
3868(D) The SID must be increased by 42 in..
3869 --------------------------------- (D) As OID is increased, recorded detail is diminished as a result of magnification distortion. If the OID cannot be minimized, an increase in SID is required to reduce the effect of magnification distortion. However, the relationship between OID and SID is not an equal relationship. In fact, to compensate for every 1 in. of OID, an increase of 7 in. of SID is required. Therefore, an OID of 6 in. requires an SID increase of 42 in.. This is why a chest radiograph with a 6-in. air gap usually is performed at a 10-ft SID
3870214. If a particular grid has lead strips 0.40 mm thick, 4.0 mm high, and 0.25 mm apart, what is its grid ratio?
3871(A) 8:1
3872(B) 10:1
3873(C) 12:1
3874(D) 16:1
3875 --------------------------------- (D) Grid ratio is defined as the ratio between the height of the lead strips and the width of the distance between them (i.e., their height divided by the distance between them). If the height of the lead strips is 4.0 mm and the lead strips are 0.25 mm apart, the grid ratio must be 16:1 (4.0 divided by 0.25). The thickness of the lead strip is unrelated to grid ratio.
3876215. The line-focus principle expresses the relationship between
3877(A) the actual and the effective focal spot
3878(B) exposure given the IR and resulting density
3879(C) SID used and resulting density
3880(D) grid ratio and lines per inch
3881 --------------------------------- (A) The line-focus principle is a geometric principle illustrating that the actual focal spot is larger than the effective (projected) focal spot. The actual focal spot (target) is larger, to accommodate heat over a larger area, and is angled so as to project a smaller focal spot, thus maintaining recorded detail by reducing blur. The relationship between the exposure given the IR and the resulting density is expressed in the reciprocity law; the relationship between the SID and resulting density is expressed by the inverse-square law. Grid ratio and lines per inch are unrelated to the line-focus principle.
3882216. Which of the following has the greatest effect on radiographic density/brightness?
3883(A) Aluminum filtration
3884(B) Kilovoltage
3885(C) SID
3886(D) Scattered radiation
3887 --------------------------------- (C) Radiographic density is greatly affected by changes in the SID, as expressed by the inverse-square law of radiation. As distance from the radiation source increases, exposure rate decreases, and radiographic density decreases. Exposure rate is inversely proportional to the square of the SID. Aluminum filtration, kilovoltage, and scattered radiation all have a significant effect on density, but they are not the primary controlling factors.
3888217. Shape distortion is influenced by the relationship between the
38891. x-ray tube and the part to be imaged
38902. part to be imaged and the IR
38913. IR and the x-ray tube
3892(A) 1 only
3893(B) 1 and 2 only
3894(C) 1 and 3 only
3895(D) 1, 2, and 3
3896 --------------------------------- (D) Shape distortion is caused by misalignment of the x-ray tube, the part to be radiographed, and the IR/film. An object can be falsely imaged (foreshortened or elongated) by incorrect placement of the tube, the body part, or the IR. Only one of the three need be misaligned for distortion to occur.
3897219. IRs frequently have a rear lead-foil layer that functions to
3898(A) improve penetration
3899(B) absorb backscatter
3900(C) preserve resolution
3901(D) increase the screen speed
3902 --------------------------------- (B) Many IR have a thin lead-foil layer behind their rear section to absorb backscattered radiation that is energetic enough to exit the rear, strike the metal back, and bounce back to fog the image.
3903The lead foil absorbs the backscatter before it can fog the PSP.
3904220. The continued emission of light by a phosphor after the activating source has ceased is termed
3905(A) fluorescence
3906(B) phosphorescence
3907(C) image intensification
3908(D) quantum mottle
3909 --------------------------------- (B) Fluorescence occurs when an intensifying screen absorbs x-ray photon energy, emits light, and then ceases to emit light as soon as the energizing source ceases. Phosphorescence occurs when an intensifying screen absorbs x-ray photon energy, emits light, and continues to emit light for a short time after the energizing source ceases. Quantum mottle is the freckle-like appearance on some radiographs made using a very fast imaging system. The brightness of a fluoroscopic image is amplified through image intensification.
3910222. How often are radiographic equipment collimators required to be evaluated?
3911(A) Annually
3912(B) Biannually
3913(C) Semiannually
3914(D) Quarterly
3915 --------------------------------- (C) Quality Control refers to our equipment and its safe and accurate operation. Various components must be tested at specified intervals, and test results must be within specified parameters. Any deviation from those parameters must be corrected. Examples of equipment components that are tested annually are the focal spot size, linearity, reproducibility, filtration, kV, and exposure time. Congruence is a term used to describe the relationship between the collimator light field and the actual x-ray field—they must be congruent (i.e., match) to within 2% of the SID. Radiographic equipment collimators should be inspected and verified as accurate semiannually, that is, twice a year. Kilovoltage settings can most effectively be tested using an electronic kV meter; to meet required standards, the kV should be accurate to within +/- 4 kV. Reproducibility testing should specify that radiation output be consistent to within +/- 5%.
3916223. In digital imaging, as the size of the image matrix increases,
39171. FOV increases
39182. pixel size decreases
39193. spatial resolution increases
3920(A) 1 only
3921(B) 1 and 2 only
3922(C) 2 and 3 only
3923(D) 1, 2, and 3
3924 --------------------------------- (C) The FOV and matrix size are independent of one another; that is, either can be changed, and the other will remain unaffected. However, pixel size is affected by changes in either the FOV or matrix size. For example, if the matrix size is increased, pixel size decreases. If FOV increases, pixel size increases. Pixel size is inversely related to resolution. As pixel size decreases, resolution increases. (
3925224. Exposed silver halide crystals are changed to black metallic silver by the
3926(A) preservative
3927(B) reducers
3928(C) activators
3929(D) hardener
3930 --------------------------------- (B) As the film emulsion is exposed to light or x-rays, latent image formation takes place. The exposed silver halide crystals are reduced to black metallic silver by the developer/reducing agents in the automatic processor's developer solution. The preservative helps to prevent oxidation of the developer solution. The activator provides the necessary alkalinity for the developer solution, and hardener is added to the developer in automatic processing to keep emulsion swelling to a minimum.
3931225. Grid cutoff due to off-centering would result in
3932(A) overall loss of density
3933(B) both sides of the image being underexposed
3934(C) overexposure under the anode end
3935(D) underexposure under the anode end
3936 --------------------------------- (A) Grids are composed of alternate strips of lead and interspace material and are used to trap scattered radiation after it emerges from the patient and before it reaches the IR. Accurate centering of the x-ray tube is required. If the x-ray tube is off-center but within the recommended focusing distance, there usually will be an overall loss of density. Over- or under-exposure under the anode is usually the result of exceeding the focusing distance limits in addition to being off-center.
3937226. The advantage(s) of high-kilovoltage chest radiography is (are) that
39381. exposure latitude is increased
39392. it produces long-scale contrast
39403. it reduces patient dose
3941(A) 1 only
3942(B) 1 and 2 only
3943(C) 2 and 3 only
3944(D) 1, 2, and 3
3945 --------------------------------- (D) The chest is composed of tissues with widely differing densities (bone and air). In an effort to "even out" these tissue densities and better visualize pulmonary vascular markings, high kilovoltage generally is used. This produces more uniform penetration and results in a longer scale of contrast with visualization of the pulmonary vascular markings as well as bone (which is better penetrated) and air densities. The increased kilovoltage also affords the advantage of greater exposure latitude (an error of a few kilovolts will make little, if any, difference). The fact that the kilovoltage is increased means that the milliampere-seconds value is reduced accordingly, and thus patient dose is reduced as well. A grid usually is used whenever high kilovoltage is required.
3946227. The exposure factors of 400 mA, 70 ms, and 78 kV were used to produce a particular radiographic density and contrast. A similar radiograph can be produced using 500 mA, 90 kV, and
3947(A) 14 ms
3948(B) 28 ms
3949(C) 56 ms
3950(D) 70 ms
3951 --------------------------------- (B) First, evaluate the change(s): The kilovoltage was increased by 15% . A 15% increase in kilovoltage will double the radiographic density; therefore, it is necessary to use half the original milliampere-seconds value to maintain the original density. The original milliampere-seconds value was 28 mAs (300 mA × 0.07 second [70 ms] 28 mAs), so we now need 14 mAs, using 500 mA. Because :
3952228. Disadvantages of using low-kilovoltage technical factors include
39531. insufficient penetration
39542. increased patient dose
39553. diminished latitude
3956(A) 1 only
3957(B) 1 and 2 only
3958(C) 1 and 3 only
3959(D) 1, 2, and 3
3960 --------------------------------- (D) As the kilovoltage is decreased, x-ray-beam energy (i.e., penetration) is also decreased. Consequently, a shorter scale of contrast is obtained, and at lower kilovoltage levels, there is less exposure latitude (less margin for error in exposure). As kilovoltage is reduced, the milliampere-seconds value must be increased accordingly to maintain adequate density. This increase in milliampere-seconds results in greater patient dose.
3961230. Geometric unsharpness is directly influenced by
39621. OID
39632. SOD
39643. SID
3965(A) 1 only
3966(B) 1 and 2 only
3967(C) 1 and 3 only
3968(D) 1, 2, and 3
3969 --------------------------------- (A) Geometric unsharpness is affected by all three factors listed. As OID increases, so does magnification—therefore, OID is directly related to magnification. As SOD and SID decrease, magnification increases—therefore, SOD and SID are inversely related to magnification.
3970231. Which of the following is/are associated with magnification fluoroscopy?
39711. Less noise
39722. Improved contrast resolution
39733. Improved spatial resolution
3974(A) 1 only
3975(B) 1 and 2 only
3976(C) 2 and 3 only
3977(D) 1, 2, and 3
3978 --------------------------------- (D) The input phosphor of image intensifiers is usually made of cesium iodide. For each x-ray photon absorbed by cesium iodide, approximately 5,000 light photons are emitted. As the light photons strike a photoemissive photocathode, a number of electrons are released from the photocathode and focused toward the output side of the image tube by voltage applied to the negatively charged electrostatic focusing lenses. The electrons are then accelerated through the neck of the tube where they strike the small (0.5-1 in.) output phosphor that is mounted on a flat glass support. The entire assembly is enclosed within a 2-4-mm thick vacuum glass envelope. Remember that the image on the output phosphor is minified, brighter, and inverted (electron focusing causes image inversion).
3979Input screen diameters of 5-12 in. are available. Although smaller diameter input screens improve resolution, they do not permit a large FOV, that is, viewing of large patient areas.
3980Dual- and triple-field image intensifiers are available that permit magnified viewing of fluoroscopic images. To achieve magnification, the voltage to the focusing lenses is increased and a smaller portion of the input phosphor is used, thereby resulting in a smaller FOV. Because minification gain is now decreased, the image is not as bright. The mA is automatically increased to compensate for the loss in brightness when the image intensifier is switched to magnification mode. Entrance skin exposure (ESE) can increase dramatically as the FOV decreases (i.e., as magnification increases).
3981As FOV decreases, magnification of the output screen image increases, there is less noise because increased mA provides a greater number of x-ray photons, and contrast and spatial resolution improve. The focal point in the magnification mode is further away from the output phosphor (as a result of increased voltage applied to the focusing lenses) and therefore the output image is magnified.
3982232. Which of the following may be used to reduce the effect of scattered radiation on a finished radiograph?
39831. Grids
39842. Collimators
39853. Compression bands
3986(A) 1 only
3987(B) 1 and 3 only
3988(C) 2 and 3 only
3989(D) 1, 2, and 3
3990 --------------------------------- (D) Collimators restrict the size of the irradiated field, thereby limiting the volume of irradiated tissue, and hence less scattered radiation is produced. Once radiation has scattered and emerged from the body, it can be trapped by the grid's lead strips. Grids effectively remove much of the scattered radiation in the remnant beam before it reaches the IR. Compression can be applied to reduce the effect of excessive fatty tissue (e.g., in the abdomen); in effect, reducing the thickness of the part to be radiographed.
3991233. Which of the following is (are) directly related to photon energy?
39921. Kilovoltage
39932. Milliamperes
39943. Wavelength
3995(A) 1 only
3996(B) 1 and 2 only
3997(C) 1 and 3 only
3998(D) 1, 2, and 3
3999 --------------------------------- (A) Kilovoltage is the qualitative regulating factor; it has a direct effect on photon energy.
4000That is, as kilovoltage is increased, photon energy increases. Photon energy is inversely related to wavelength. That is, as photon energy increases, wavelength decreases. Photon energy is unrelated to milliamperage.
4001234. What information, located on each box of film, is important to note and has a direct relationship to image quality?
4002(A) Number of films in the box
4003(B) Manufacturer's name
4004(C) Expiration date
4005(D) Emulsion lot
4006 --------------------------------- (C) Every box of film comes with the expiration date noted. Film used after its expiration date usually will suffer a loss of speed and contrast and will exhibit fog. Film should be ordered in quantities that will ensure that it is used before it becomes outdated, and it should be rotated in storage so that the oldest is used first.
4007235. If 40 mAs and a 200-speed screen-film system were used for a particular exposure, what new milliampere-seconds value would be required to produce the same density if the screen-film system were changed to 800 speed?
4008(A) 10
4009(B) 20
4010(C) 80
4011(D) 160
4012 --------------------------------- (A) The screen-film system and radiographic density are directly proportional; that is, if the system speed is doubled, the radiographic density is doubled. In this case, we started at 40 mAs with a 200-speed system. If the system speed is doubled to 400, we should decrease the milliampere-seconds to 20 mAs. If the speed is again doubled to 800, we use half the 20 mAs, or 10 mAs. Or milliampere-seconds conversion factors and the following formula may be used:
4013
4014
4015Thus, mAs with a 800-speed screen-film system.
4016236. An exposure was made using 8 mAs and 60 kV. If the kilovoltage was changed to 70 to obtain longer-scale contrast, what new milliampere-seconds value is required to maintain density?
4017(A) 2
4018(B) 4
4019(C) 16
4020(D) 32
4021 --------------------------------- (B) According to the 15% rule, if the kilovoltage is increased by 15%, radiographic density will be doubled. Therefore, to compensate for this change and to maintain radiographic density, the milliampere-seconds value should be reduced to 4 mAs.
4022237. Recorded detail can be improved by decreasing
40231. the SID
40242. the OID
40253. patient/part motion
4026(A) 1 only
4027(B) 3 only
4028(C) 2 and 3 only
4029(D) 1, 2, and 3
4030 --------------------------------- (C) Motion, voluntary or involuntary, is most detrimental to good recorded detail. Even if all other factors are adjusted to maximize detail, if motion occurs during exposure, detail is lost. The most important ways to reduce the possibility of motion are using the shortest possible exposure time, careful patient instruction (for suspended respiration), and adequate immobilization when necessary. Minimizing magnification through the use of increased SID and decreased OID functions to improve recorded detail.
4031238. Compression of the breast during mammo-graphic imaging improves the technical quality of the image because
40321. geometric blurring is decreased
40332. less scattered radiation is produced
40343. patient motion is reduced
4035(A) 1 only
4036(B) 3 only
4037(C) 2 and 3 only
4038(D) 1, 2, and 3
4039 --------------------------------- (D) Compression of the breast tissue during mammographic imaging improves the technical quality of the image for several reasons. Compression brings breast structures into closer contact with the IR, thus reducing geometric blur and improving detail. As the breast tissue is compressed and essentially becomes thinner, less scattered radiation is produced. Compression serves as excellent immobilization as well.
4040239. Distortion can be caused by
40411. tube angle
40422. the position of the organ or structure within the body
40433. the radiographic positioning of the part
4044(A) 1 only
4045(B) 1 and 2 only
4046(C) 2 and 3 only
4047(D) 1, 2, and 3
4048 --------------------------------- (D) Distortion is caused by improper alignment of the tube, body part, and IR. Anatomic structures within the body are rarely parallel to the IR in a simple recumbent position. In an attempt to overcome this distortion, we position the part to be parallel with the IR or angle the central ray to "open up" the part. Examples of this technique are obliquing the pelvis to place the ilium parallel to the IR or angling the central ray cephalad to "open up" the sigmoid colon.
4049240. As window level increases
4050(A) contrast scale increases
4051(B) contrast scale decreases
4052(C) brightness increases
4053(D) brightness decreases
4054 --------------------------------- (C) In electronic/digital imaging, changes in window width affect changes in contrast scale, while changes in window level affect changes in brightness (in analog terms, density). As window width increases, the scale of contrast increases (i.e., contrast decreases). As window level increases, brightness increases. It should be noted that, to describe an increase in brightness, our old analog terminology would say that density decreases. This can be easily illustrated as you postprocess/window your own digital photographs or scanned documents. As you slide the brightness scale to increase brightness, the photo/image gets darker, that is, increased density.
4055242. What is the relationship between tissue attenuation coefficient in CT and its related Hounsfield unit (HU)?
4056(A) The greater the tissue attenuation coefficient, the lower the HU value.
4057(B) The greater the tissue attenuation coefficient, the higher the HU value.
4058(C) Tissue attenuation coefficient and HU value are unrelated.
4059(D) Tissue attenuation coefficient and HU value are identical.
4060 --------------------------------- (B) Sir Godfrey Newbold Hounsfield created the first CT unit, describing the reconstruction of data taken from multiple projection angles. Alan MacLeod Cormack worked with the complex mathematical algorithms required for image reconstruction. Their first commercial CT head scanner was available in 1971. In 1979, Hounsfield and Cormack shared the Nobel Prize in Medicine for their historic work with this new imaging science.
4061To express the beam attenuation characteristics of various tissues, the Hounsfield unit (HU) is used. HUs can also be referred to as CT numbers or density values. Godfrey Hounsfield assigned a value of 0 to distilled water, a value of +1,000 to dense osseous tissue, and a value of -1,000 to air. There is a direct relationship between the HU and tissue attenuation coefficient. The greater the attenuation coefficient of the particular tissue, the higher the HU value. One HU represents a 0.1% difference between the particular tissue attenuation characteristics and that of distilled water. HU value accuracy can be affected by equipment calibration, volume averaging, and image artifacts.
4062243. A grid usually is employed in which of the following circumstances?
40631. When radiographing a large or dense body part
40642. When using high kilovoltage
40653. When a lower patient dose is required
4066(A) 1 only
4067(B) 3 only
4068(C) 1 and 2 only
4069(D) 1, 2, and 3
4070 --------------------------------- (C) Significant scattered radiation is generated within the part when imaging large or dense body parts and when using high kilo-voltage. A radiographic grid is made of alternating lead strips and interspace material; it is placed between the patient and the IR to absorb energetic scatter emerging from the patient. Although a grid prevents much of the scattered radiation from reaching the radiograph, its use does necessitate a significant increase in patient exposure.
4071244. Exposure factors of 90 kV and 3 mAs are used for a particular nongrid exposure. What should be the new milliampere-seconds (mAs) value if a 12:1 grid is added?
4072(A) 86
4073(B) 9
4074(C) 12
4075(D) 15
4076 --------------------------------- (D) To change nongrid to grid exposure or to adjust exposure when changing from one grid ratio to another, it is necessary to recall the factor for each grid ratio:
4077
4078
4079Therefore, to change from nongrid to a 12:1 grid, multiply the original milliampere-seconds value by a factor of 5. A new milliampere-seconds value of 15 is required.
4080245. An exposure was made using 300 mA, 40 ms exposure, and 85 kV. Each of the following changes will decrease the radiographic density by one half except a change to
4081(A) 1/50-s exposure
4082(B) 72 kV
4083(C) 10 mAs
4084(D) 150 mA
4085 --------------------------------- (C) Radiographic density is directly proportional to milliampere-seconds. If exposure time is halved from 40 ms (0.04 or 1/25 s) to 0.02 (1/50) s, radiographic density will be cut in half. Changing to 150 mA also will halve the milliampere-seconds, effectively halving the radiographic density. If the kilovoltage is decreased by 15%, from 85 to 72 kV, radiographic density will be halved according to the 15% rule. To cut the density in half, the milliampere-seconds value must be reduced to 6 mAs (rather than 10 mAs).
4086246. Which of the following units is (are) used to express resolution?
40871. Line-spread function
40882. Line pairs per millimeter
40893. Line-focus principle
4090(A) 1 only
4091(B) 1 and 2 only
4092(C) 2 and 3 only
4093(D) 1, 2, and 3
4094 --------------------------------- (B) Resolution describes how closely fine details may be associated and still be recognized as separate details before seeming to blend into each other and appear "as one." The degree of resolution transferred to the IR is a function of the resolving power of each of the system components and can be expressed in line pairs per millimeter (lp/mm), line-spread function (LSP), or modulation transfer function (MTF). Lp/mm can be measured using a resolution test pattern; a number of resolution test tools are available. LSP is measured using a 10-μm x-ray beam; MTF measures the amount of information lost between the object and the IR. The effective focal spot is the foreshortened size of the actual focal spot as it is projected down toward the IR, that is, as it would be seen looking up into the emerging x-ray beam. This is called the line-focus principle and is not a unit used to express resolution.
4095247. Which of the following is (are) methods used for x-ray film silver reclamation?
40961. Photoelectric method
40972. Metallic replacement method
40983. Electrolytic method
4099(A) 1 only
4100(B) 1 and 2 only
4101(C) 2 and 3 only
4102(D) 1, 2, and 3
4103 --------------------------------- (C) About half the silver in a film emulsion remains to form the image. The other half is removed from the film during the fixing process. Therefore, fixer solution has a high silver content. Silver is a toxic metal and cannot simply be disposed of into the public sewer system. Since silver is also a precious metal, it becomes financially wise to recycle the silver removed from x-ray film. The three most commonly used silver recovery systems are the electrolytic, metallic replacement, and chemical precipitation methods. In electrolytic units, an electric current is passed through the fixer solution. Silver ions are attracted to and become plated onto the negative electrode of the unit. The plated silver is periodically scraped from the cathode and accurately measured so that the hospital can be reimbursed appropriately. The electrolytic method is a practical recovery system for moderate-and high-use processors. The metallic replacement (or displacement) method of silver recovery uses a steel mesh/steel wool type of cartridge that traps silver as fixer is run through it. This system is useful for low-volume processors and is often also used as a backup to the electrolytic unit. Chemical precipitation adds chemicals that release electrons into the fixer solution. This causes the metallic silver to precipitate out, fall to the bottom of the tank, and form a recoverable sludge. This method is used principally by commercial silver dealers.
4104249. In which of the following examinations should 70 kV not be exceeded?
4105(A) Upper GI (UGI)
4106(B) Barium enema (BE)
4107(C) Intravenous urogram (IVU)
4108(D) Chest
4109 --------------------------------- (C) The iodine-based contrast material used in IVU gives optimal opacification at 60 to 70 kV. Use of higher kilovoltage will negate the effect of the contrast medium; a lower contrast will be produced, and poor visualization of the renal collecting system will result. GI and BE examinations employ high-kilovoltage exposure factors (about 120 kV) to penetrate through the barium. In chest radiography, high-kilovoltage technical factors are preferred for maximum visualization of pulmonary vascular markings made visible with long-scale contrast.