AART study guide

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1. The term latitude describes
I. an emulsion's ability to record a range of densities
II. the degree of error tolerated with given exposure factors
III. the conversion efficiency of a given intensifying screen

A. 1 only
B. 1 and 2 only
C. 2 and 3 only
D. 1, 2, and 3

The answer is b
2. EXPLANATION: The term latitude may refer to either film emulsion latitude or exposure latitude. Exposure latitude refers to the margin of error inherent in a particular group of exposure factors. Selection of high-kilovoltage and low-milliampere-seconds factors will allow greater exposure latitude than low-kilovoltage and high-milliampere-seconds factors. Film emulsion latitude is chemically built into the film emulsion and refers to the emulsion's ability to record a long range of densities from black to white (long-scale contrast).

2. During IV urography, the prone position generally is recommended to demonstrate the filling of
a. the ureters
b. the renal pelvis
c. the superior calyces
i. 1 only
ii. 1 and 2 only
iii. 1 and 3 only
iv. 1, 2, and 3

The answer is II
2. EXPLANATION: The kidneys lie obliquely in the posterior portion of the trunk with their superior portion angled posteriorly and their inferior portion and ureters angled anteriorly. Therefore, to facilitate filling of the most anteriorly placed structures, the patient is examined in the prone position. Opacified urine then flows to the most dependent part of the kidney and ureter—the ureteropelvic region, inferior calyces, and ureters. (Saia, 4th ed., p. 191)

3. Which of the following projections of the elbow should demonstrate the coronoid process free of superimposition and the olecranon process within the olecranon fossa?
a. AP
b. Lateral
c. Medial oblique
d. Lateral oblique

The answer is C.
ii. EXPLANATION: On the AP projection of the elbow, the radial head and ulna are normally somewhat superimposed. The lateral oblique demonstrates the radial head free of ulnar superimposition. The lateral projection demonstrates the olecranon process in profile. The medial oblique demonstrates considerable overlap of the proximal radius and ulna, but should clearly demonstrate the coronoid process free of superimposition and the olecranon process within the olecranon fossa. (Saia, p 96)

4. The instrument that is used frequently in quality-control programs to measure varying degrees of x-ray exposure is the
a. aluminum step wedge.
b. spinning top.
c. densitometer.
d. sensitometer.

The answer is C.
ii. EXPLANATION: Every radiographic image is composed of a number of different densities. These densities may be measured and given a numeric value with a device called a densitometer. A sensitometer is another device used in QA programs; it is used to give a precise exposure to a film emulsion. An aluminum step wedge (penetrometer) may be used to show the effect of kilovoltage on contrast. A spinning top is used to test the accuracy of the x-ray machine's timer or rectifiers. (Bushong, 8th ed., p. 275)

5. Congruence of the x-ray beam with the light field is tested using
a. a pinhole camera
b. a star pattern
c. radiopaque objects
d. a slit camera

. The answer is C.
ii. EXPLANATION: Radiographic results should be consistent and predictable with respect to positioning accuracy, exposure factors, and equipment operation. X-ray equipment should be tested and calibrated periodically as part of an ongoing quality assurance (QA) program. The focal spot should be tested periodically to evaluate its size and its impact on recorded detail; this is accomplished using a slit camera, a pinhole camera, or a star pattern. To test the congruence of the light and x-ray fields, a radiopaque object such as a paper clip or a penny is placed at each corner of the light field before the test exposure is made. After processing, the corners of the x-ray field should be exactly delineated by the radioopaque objects. (Carlton and Adler, 4th ed., p. 484)

6. When a slow screen-film system is used with a fast screen-film AEC system, the resulting images
a. are too light
b. are too dark
c. have improved detail
d. have poor detail

The answer is A.
ii. EXPLANATION: When an AEC (phototimer or ionization chamber) is used, the system is programmed for the use of a particular screen-film speed (e.g., 400 speed). If a slower-speed screen IR is placed in the Bucky tray, the AEC has no way of recognizing it as different and will time the exposure for the system for which it is programmed. For example, if the AEC is programmed for a 400-speed screen-film combination, and if a 200-speed screen IR is placed in the Bucky tray, the resulting radiograph will have half the required radiographic density. (Shephard, pp. 65-66)

7. To demonstrate the glenoid fossa in profile, the patient is positioned
a. 45 degrees oblique, affected side up.
b. 45 degrees oblique, affected side down.
c. 25 degrees oblique, affected side up.
d. 25 degrees oblique, affected side down.

The answer is B.
ii. EXPLANATION: When viewing the glenoid fossa from the anterior, it is seen to angle posteriorly and laterally approximately 45 degrees. To view it in profile, then, it must be placed so that its surface is perpendicular to the IR. The patient is positioned in a 45-degree oblique, affected-side-down position, which places the glenoid fossa approximately perpendicular to the IR. The arm is abducted slightly, the elbow is flexed, and the hand and forearm are placed over the abdomen. The CR is directed perpendicular to the glenohumeral joint. (Frank, Long, and Smith, 11th ed., vol. 1, pp. 192-193)

8. Europium-activated barium fluorohalide is associated with
a. rare earth intensifying screens
b. image intensifiers
c. PSP storage plates
d. filament material

The answer is C.
ii. EXPLANATION: Computed radiography (CR) cassettes use no intensifying screens or film—hence, the term filmless radiography. The Image Plates (IPs) have a protective function (for the PSP/storage plate within) and can be used in the Bucky tray or directly under the anatomic part; they need not be light-tight because the PSP is not light sensitive. The IP has a thin lead-foil backing (similar to traditional cassettes) to absorb backscatter. Inside the IP is the photostimulable phosphor (PSP) storage plate. This PSP storage plate within the IP has a layer of europium-activated barium fluorohalide that serves as the IR as 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. (Carlton and Adler, 4th ed., p. 358)

9. Moving the image intensifier closer to the patient during traditional fluoroscopy
1. decreases the SID
2. decreases patient dose
3. improves image quality
A. 1 only
B. 1 and 2 only
C. 1 and 3 only
D. 1, 2, and 3

. The answer is D
2. EXPLANATION: Moving the image intensifier closer to the patient during traditional fluoroscopy reduces the distance between the x-ray tube (source) and the image intensifier (IR), that is, the SID. It follows that the distance between the part being imaged (object) and the image intensifier (IR), that is, the object-to-image distance (OID), is also reduced. The shorter OID produces less magnification and better image quality. As the SID is reduced, the intensity of the x-ray photons at the image intensifier's input phosphor increases, stimulating the automatic brightness control (ABC) to decrease the milliamperage and thereby decreasing patient dose (Figure 5-15). (Fosbinder and Kelsey, pp. 265-267)

10. What is the minimum requirement for lead aprons, according to CFR 20?
a. 0.05 mm Pb
b. 0.50 mm Pb
c. 0.25 mm Pb
d. 1.0 mm Pb

The answer is C.
ii. EXPLANATION: Lead aprons are secondary radiation barriers and must contain at least 0.25-mm Pb equivalent, usually in the form of lead-impregnated vinyl (according to CFR 20). 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. (Bushong, 8th ed., p. 560)

11. Which of the following is a measurement of dose to biologic tissue?
a. Roentgen (C/kg)
b. Rad (Gy)
c. Rem (Sv)
d. RBE

The answer is C.
ii. EXPLANATION: Roentgen is the unit of exposure; it measures the quantity of ionization in air. Rad is an acronym for radiation absorbed dose; it measures the energy deposited in any material. Rem is an acronym for radiation equivalent man; it includes the RBE specific to the tissue irradiated, and therefore is a valid unit of measurement for the dose to biologic material. (Bushong, p 24)

12. How are mAs and radiographic density related in the process of image formation?
a. mAs and radiographic density are inversely proportional
b. mAs and radiographic density are directly proportional
c. mAs and radiographic density are related to image unsharpness
d. mAs and radiographic density are unrelated

The answer is B.
ii. EXPLANATION: Radiographic density is described as the overall degree of blackening of a radiograph or a part of it. The milliampere-seconds value regulates the number of x-ray photons produced at the target and thus regulates radiographic density. If it is desired to double the radiographic density, one simply doubles the milliampere-seconds; therefore, milliampere-seconds and radiographic density are directly proportional. (Selman, 9th ed., p. 214)

13. Which of the following structures will usually contain air, in the PA position on a sthenic patient, during a double-contrast upper GI (UGI) examination?
a. Duodenal bulb
b. Descending duodenum
c. Pyloric vestibule
d. Gastric fundus

The answer is D.
ii. EXPLANATION: The stomach is normally angled with the fundus lying posteriorly and the body, pylorus, and duodenum inferior to the fundus and angling anteriorly. Therefore, when the patient ingests barium and lies AP recumbent, the heavy barium gravitates easily to the fundus and fills it. With the patient PA recumbent, barium gravitates inferiorly to the body, pylorus, and duodenum, displacing air into the fundus. (Frank, Long, and Smith, 11th ed., vol. 2, pp. 144-145)

14. 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
a. line-focus principle
b. inverse-square law
c. reciprocity law
d. law of conservation of energy

The answer is C.
ii. EXPLANATION: 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. (Shephard, p. 193)

15. To radiograph an infant for suspected free air within the abdominal cavity, which of the following projections of the abdomen will demonstrate the condition with the least patient exposure?
a. PA erect with grid
b. Left lateral decubitus with grid
c. Left lateral decubitus without grid
d. Recumbent AP without grid

The answer is C.
ii. EXPLANATION: Air-fluid levels are demonstrated in the erect or decubitus position. Grid radiography requires about a 3 to 4 times greater dose than nongrid radiography. A left lateral decubitus projection without a grid, then, would demonstrate fluid levels with a considerably smaller dose to the infant. PA erect with grid would be the next-best choice - the PA position reduces dose to radiosensitive future reproductive cells. A recumbent AP projection would not demonstrate air-fluid levels. Left lateral decubitus is preferred to right lateral decubitus because the liver moves down slightly in this position, creating a space between the liver and right hemidiaphragm (right subphrenic space). Any abdominal free air would then be visualized below the right hemidiaphragm in the subphrenic space along the lateral aspect of the liver. (Bontrager and Lampignano, 6th ed., p. 676)

16. An increase in kilovoltage will have which of the following effects?
a. More scattered radiation will be produced.
b. The exposure rate will increase.
c. Radiographic contrast will increase.
i. 1 only
ii. 1 and 2 only
iii. 2 and 3 only
iv. 1, 2, and 3

The answer is ii
2. EXPLANATION: 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. (Selman, 9th ed., p. 117)

17. Component part(s) of x-ray film include which of the following?
a. Phosphor layer
b. Gelatin emulsion
c. Adhesive layer
i. 1 only
ii. 1 and 3 only
iii. 2 and 3 only
iv. 1, 2, and 3

The answer is iii
2. EXPLANATION: The manufacture of x-ray film starts with a clear polyester base that serves as support for the emulsion. Applied next is an adhesive layer, which functions to hold the emulsion to the base. Next is the emulsion, consisting of silver halide grains suspended in gelatin. Finally, a supercoat of clear, hard gelatin is applied as an antiabrasive layer. A phosphor layer is used in the construction of intensifying screens. (Shephard, pp. 85-88)

18. Which of the following radiologic examinations requires preparation consisting of a low-residue diet, cathartics, and enemas?
a. Upper GI series
b. Small bowel series
c. Barium enema (BE)
d. Intravenous (IV) cystogram

The answer is C.
ii. EXPLANATION: To have high diagnostic quality, a barium enema (BE) examination requires rigorous and complete patient preparation. This usually consists of a modified low-residue diet for a few days before the examination, cathartics the day before, and cleansing enemas the morning of the examination. Instructions for a upper GI series, small bowel series, and IV cystogram are usually to be NPO after midnight. (Frank, Long, and Smith, 11th ed., vol. 2, p. 159)

19. What type of precautions prevent the spread of infectious agents in droplet form?
a. Contact precautions
b. Airborne precautions
c. Protective isolation
d. Strict isolation

The answer is B.
ii. EXPLANATION: 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. (Adler and Carlton, 4th ed., pp. 232-233)

20. The Bucky slot cover is in place to protect the
1. patient
2. fluoroscopist
3. technologist
A. 1 only
B. 1 and 2 only
C. 2 and 3 only
D. 1, 2, and 3

The answer is C.
2. EXPLANATION: 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. (Bushong, 8th ed., p. 570)

21. The late effects of radiation are considered to
1. have no threshold dose.
2. be directly related to dose.
3. occur within hours of exposure.
A. 1 only
B. 1 and 2 only
C. 2 and 3 only
D. 1, 2, and 3

The answer is B.
2. EXPLANATION: Exposure to high doses of radiation results in early effects. Examples of early effects are blood changes and erythema. If the exposed individual survives, then late, or long-term, effects must be considered. Individuals who receive small amounts of low-level radiation (such as those who are occupationally exposed) are concerned with the late effects of radiation exposure—effects that can occur many years after the initial exposure. Late effects of radiation exposure, such as carcinogenesis, are considered to be related to the linear nonthreshold dose-response curve. That is, there is no safe dose; theoretically, even one x-ray photon can induce a later response.

22. The dose of radiation that will cause a noticeable skin reaction is referred to as the
a. LET
b. SSD
c. SED
d. SID

The answer is C.
ii. EXPLANATION: 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. (Bushong, 8th ed., p. 521)

23. The image intensifier's input phosphor differs from the output phosphor in that the input phosphor
a. is much larger than the output phosphor
b. emits electrons, whereas the output phosphor emits light photons
c. absorbs electrons, whereas the output phosphor absorbs light photons
d. is a fixed size, and the size of the output phosphor can vary

The answer is A.
ii. EXPLANATION: The image intensifier's input phosphor is 6 to 9 times larger than the output phosphor. It receives the remnant radiation emerging from the patient and converts it into a fluorescent light image. Very close to the input phosphor, separated only by a thin, transparent layer, is the photocathode. The photocathode is made of a photoemissive alloy, usually a cesium and antimony compound. The fluorescent light image strikes the photocathode and is converted to an electron image, which is focused by the electrostatic lenses to the small output phosphor. (Bushong, 8th ed., pp. 360-363)

24. To obtain an exact axial projection of the clavicle, place the patient
a. supine and angle the central ray 30° caudally.
b. prone and angle the central ray 30° cephalad.
c. supine and angle the central ray 15° cephalad.
d. in a lordotic position and direct the central ray at right angles to the coronal plane of the clavicle.

The answer is D.
ii. EXPLANATION: The exact axial projection is performed by placing the patient in a lordotic position, leaning against the vertical grid device. This places the clavicle at right angles, or nearly so, to the plane of the IR. The central ray is directed to enter the inferior border of the clavicle, at right angles to its coronal plane. Other axial projections may include a prone position with a 25° to 30° caudal angle. However, none of these produce an exact axial projection of the clavicle. (Ballinger & Frank, vol 1, p 159)

25. The submentovertical (SMV) oblique axial projection of the zygomatic arches requires that the skull be rotated
a. 15 degrees toward the affected side.
b. 15 degrees away from the affected side.
c. 45 degrees toward the affected side.
d. 45 degrees away from the affected side.

The answer is A.
ii. EXPLANATION: The oblique axial projection is valuable when the zygomatic arches cannot be demonstrated bilaterally with the submentovertical projection because they are not prominent enough or because of a depressed fracture. The patient still may be positioned as for an SMV projection, but the head is obliqued 15 degrees toward the side being examined. This serves to move the zygomatic arch away from superimposed structures and provides a slightly oblique axial projection of the arch. (Bontrager and Lampignano, 6th ed., p. 426)

26. To demonstrate the pulmonary apices with the patient in the AP position, the
a. central ray is directed 15° to 20° cephalad.
b. central ray is directed 15° to 20° caudad.
c. exposure is made on full exhalation.
d. patient's shoulders are rolled forward.

The answer is A.
ii. EXPLANATION: When the shoulders are relaxed, the clavicles are usually carried below the pulmonary apices. To examine the portions of the lungs lying behind the clavicles, the central ray is directed cephalad 15° to 20° to project the clavicles above the apices when the patient is examined in the AP position. (Ballinger & Frank, vol 1, p 472)

27. The CR should be directed to the center of the part of greatest interest to avoid
a. rotation distortion
b. magnification
c. foreshortening
d. elongation

The answer is A.
ii. EXPLANATION: Image 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 midpoint of the part of greatest interest. For example, if bilateral hands are requested, they should be examined individually; if imaged simultaneously, the CR will be directed to no anatomic part (between the two hands) and rotation distortion will occur. Magnification occurs when an OID is introduced, or with a decrease in SID. Foreshortening and elongation are the two types of shape distortion—caused by nonalignment of the x-ray tube, part/subject, and IR.

29. In which type of equipment does kilovoltage decrease during the actual length of the exposure?
1. Condenser-discharge mobile equipment
2. Battery-operated mobile equipment
3. Fixed x-ray equipment
A. 1 only
B. 1 and 2 only
C. 2 and 3 only
D. 1, 2, and 3

The answer is A.
2. EXPLANATION: Mobile x-ray machines are compact and cordless and are either the battery-operated type or the condenser-discharge type. Condenser-discharge mobile x-ray units do not use batteries; this type of mobile unit requires that it be charged before each exposure. A condenser (or capacitor) is a device that stores electrical energy. The stored energy is used to operate the x-ray tube only. Because this machine does not carry many batteries, it is much lighter and does not need a motor to drive or brake it. The major disadvantage of the capacitor/condenser-discharge unit is that as the capacitor discharges its electrical charge, the kilovoltage gradually decreases throughout the length of the exposure—therefore limiting tube output and requiring recharging between exposures. (Frank, Long, and Smith, 11th ed., vol. 3, p. 235)

30. If a radiograph exposed using a 12:1 ratio grid exhibits a loss of density at its lateral edges, it's probably because the
a. SID was too great
b. grid failed to move during the exposure
c. x-ray tube was angled in the direction of the lead strips
d. central ray was off-center

The answer is A.
ii. EXPLANATION: 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. (Carlton and Adler, 4th ed., p. 260)

31. Focusing distance is associated with which of the following?
a. Computed tomography
b. Chest radiography
c. Magnification radiography
d. Grids

The answer is D.
ii. EXPLANATION: 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. (Selman, 9th ed., pp. 239-240)

32. 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
a. 1 mSv
b. 5 mSv
c. 15 mSv
d. 50 mSv

The answer is B.
ii. EXPLANATION: 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 the eye, a particularly radiosensitive organ, is 150 mSv (15 rem). The annual occupational dose-equivalent limit for the thyroid, skin, and extremities is 500 mSv (50 rem). (Bushong, 8th ed., p. 557)

33. A radiolucent sponge can be placed under the patient's waist for a lateral projection of the lumbosacral spine to
1. make the vertebral column parallel with the IR
2. place the intervertebral disk spaces perpendicular to the IR
3. decrease the amount of SR reaching the IR
A. 1 only
B. 1 and 2 only
C. 2 and 3 only
D. 1, 2, and 3

. The answer is B.
2. EXPLANATION: When placed in the recumbent lateral position, the average adult's lumbar spine will not be parallel to the x-ray tabletop. Because the shoulders and hips generally are wider than the waist, the vertebral column slopes downward in the central areas—making the lower thoracic and upper lumbar spine closer to the tabletop than the upper thoracic and lower lumbar spine. One solution is to place a radiolucent sponge under the patient's waist. This will elevate the sagging spinal area and make the vertebral column parallel to the x-ray tabletop and IR. It will also open the intervertebral disks better, placing more of them parallel to the path of the x-ray photons and perpendicular to the IR. This position also places the intervertebral foramina parallel with the path of the CR. The radiolucent sponge is strictly a positioning aid and has no impact on the amount of SR reaching the IR. (Bontrager and Lampignano, 6th ed., p. 335)

34. What percentage of x-ray attenuation does a 0.5-mm lead equivalent apron at 100 kVp provide?
a. 51%
b. 66%
c. 75%
d. 94%

The answer is B.
2. EXPLANATION: When placed in the recumbent lateral position, the average adult's lumbar spine will not be parallel to the x-ray tabletop. Because the shoulders and hips generally are wider than the waist, the vertebral column slopes downward in the central areas—making the lower thoracic and upper lumbar spine closer to the tabletop than the upper thoracic and lower lumbar spine. One solution is to place a radiolucent sponge under the patient's waist. This will elevate the sagging spinal area and make the vertebral column parallel to the x-ray tabletop and IR. It will also open the intervertebral disks better, placing more of them parallel to the path of the x-ray photons and perpendicular to the IR. This position also places the intervertebral foramina parallel with the path of the CR. The radiolucent sponge is strictly a positioning aid and has no impact on the amount of SR reaching the IR. (Bontrager and Lampignano, 6th ed., p. 335)

35. Aspirated foreign bodies in older children and adults are most likely to lodge in the
a. right main stem bronchus
b. left main stem bronchus
c. esophagus
d. proximal stomach

The answer is A.
ii. EXPLANATION: Because the right main stem bronchus is wider and more vertical, aspirated foreign bodies are more likely to enter it than the left main stem bronchus, which is narrower and angles more sharply from the trachea. An aspirated foreign body does not enter the esophagus or the stomach because they are not respiratory structures. The esophagus and stomach are digestive structures; a foreign body would most likely be swallowed to enter these structures. (Tortora and Derrickson, 11th ed., p. 857)

36. The AP axial projection of the chest for pulmonary apices
a. requires 15 to 20 degrees of cephalad angulation
b. projects the apices above the clavicles
c. should demonstrate the medial ends of the clavicles equidistant from the vertebral column
i. 1 only
ii. 1 and 2 only
iii. 1 and 3 only
iv. 1, 2, and 3

The answer is A.
ii. EXPLANATION: Because the right main stem bronchus is wider and more vertical, aspirated foreign bodies are more likely to enter it than the left main stem bronchus, which is narrower and angles more sharply from the trachea. An aspirated foreign body does not enter the esophagus or the stomach because they are not respiratory structures. The esophagus and stomach are digestive structures; a foreign body would most likely be swallowed to enter these structures. (Tortora and Derrickson, 11th ed., p. 857)

37. The device used to change alternating current to unidirectional current is
a. a capacitor
b. a solid-state diode
c. a transformer
d. a generator

The answer is B.
ii. EXPLANATION: Some x-ray circuit devices, such as the transformer and autotransformer, will operate only on AC. The efficient operation of the x-ray tube, however, requires the use of unidirectional current, so current must be rectified before it gets to the x-ray tube. The process of full-wave rectification changes the negative half-cycle to a useful positive half-cycle. An x-ray circuit rectification system is located between the secondary coil of the high-voltage transformer and the x-ray tube. Rectifiers are solid-state diodes made of semiconductive materials such as silicon, selenium, or germanium that conduct electricity in only one direction. Thus, a series of rectifiers placed between the transformer and x-ray tube function to change AC to a more useful unidirectional current. (Bushong, 8th ed., p. 119)

38. Using a 48-in. SID, how much OID must be introduced to magnify an object two times?
a. 8-in. OID
b. 12-in. OID
c. 16-in. OID
d. 24-in. OID

The answer is D.
ii. EXPLANATION: 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. (Selman, pp. 223-225; Shephard, pp. 229-231)

39. The appearance of underexposure on an image created using a high-speed film-screen system can be caused by all the following except
a. insufficient mAs
b. insufficient kV
c. insufficient SID
d. insufficient development

The answer is C.
ii. EXPLANATION: Higher-speed film/screen imaging systems are used often to produce more density with less exposure. Since the milliampere-seconds value is the factor controlling image density, an insufficient amount would result in underexposure. Since kilovoltage has a definite effect on image density, an insufficient amount would result in underexposure. Underdevelopment of the latent film emulsion image also would result in insufficient density. However, insufficient SID (i.e., SID too low) would cause an increase in image density/overexposure. (Shephard p. 179)

40. Using a short (25-30 in.) SID with a large (14 x 17 in.) IR is likely to
a. increase the scale of contrast
b. increase the anode heel effect
c. cause malfunction of the AEC
d. cause premature termination of the exposure

i. Correct. The answer is B.
ii. EXPLANATION: 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. (Carlton and Adler, 4th ed., p. 407)

42. The cause of films coming from the automatic processor still damp can be
a. air velocity too high
b. unbalanced processing temperatures
c. insufficient hardening action
d. underreplenishment

The answer is C.
ii. EXPLANATION: If the fixer fails to harden the gelatin emulsion sufficiently, water will remain within the still-swollen emulsion. The dryer mechanism will be unable to completely rid the emulsion of wash water, and the film will emerge from the processor damp and tacky. On the other hand, excessive hardening action may produce brittle radiographs. High air velocity usually encourages more complete drying. Unbalanced processing temperatures can result in blistering of the emulsion. Developer underreplenishment results in "light" images and can be the cause of transport problems as a result of insufficient hardener. (Carlton and Adler, 4th ed., p. 289)

43. Use your mouse to drag the following tissues into order (A-D) from lowest weighting factor (Wt) to highest weighting factor.
a. Skin
b. Breast
c. Lung
d. Bone marrow

Skin, Breast, Lung, Bone marrow
ii. The tissue weighting factor (Wt) represents the relative tissue radiosensitivity of irradiated material (e.g., muscle versus intestinal epithelium versus bone, etc.). The tissue weighting factor of the gonads is 0.20. The tissue weighting factor of bone marrow, colon, lung, and stomach is 0.12. The bladder, breast, esophagus, liver, and thyroid have a tissue weighting factor of 0.05. The skin and surface of bone weighting factor is 0.01. 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-rays versus alpha particles). The Wr of different ionizing radiations depends on the LET of that particular radiation. The radiation weighting factor of x and gamma radiation, as well as electrons, is 1. The radiation weighting factor of protons is 2 and of alpha particles is 20. The radiation weighting factor of neutrons can be anywhere between 5 and 20 depending on their energy. The following formula is used to determine effective dose (E): E = Wr x Wt x absorbed dose (Bushong, pp. 556, 558)

44. Bone densitometry is often performed to
I. measure degree of bone (de)mineralization
II. evaluate results of osteoporosis treatment/therapy
III. evaluate condition of soft tissue adjacent to bone
A. 1 only
B. 1 and 2 only
C. 2 and 3 only
D. 1, 2, and 3

The answer is B.
2. EXPLANATION: Dual x-ray absorptiometry (DXA) imaging is used to evaluate bone mineral density (BMD). 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. 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, the attenuation is calculated to represent the degree of bone density. Soft tissue attenuation information is not used to measure bone density. (Frank, Long, and Smith, 11th ed., vol. 3, pp. 454-455)

45. Which of the following quantities of filtration is most likely to be used in mammography?
a. 0.5 mm Mo
b. 1.5 mm Al
c. 1.5 mm Cu
d. 2.0 mm Cu

The answer is A.
ii. EXPLANATION: Soft tissue radiography requires the use of long-wavelength, low-energy x-ray photons. Very little filtration is used in mammography. Certainly, anything more than 1.0 mm of aluminum would remove the useful soft photons, and the desired high contrast could not be achieved. Dedicated mammographic units usually have molybdenum targets (for the production of soft radiation) and a small amount of molybdenum filtration. (Carlton & Adler, p 581)

46. If the quantity of black metallic silver on a particular x-ray film is such that it allows 1% of the illuminator light to pass through the film, that film has a density of
a. 0.1
b. 1.0
c. 2.0
d. 3.0

The answer is C.
ii. EXPLANATION: If a film is placed on an illuminator and 100% of the illuminator's light is transmitted through the film, that film must have a density of 0. According to the equation density = log10(incident intensity/transmitted light intensity) if 10% of the illuminator's light passes through the film, that film has a density of 1. If 1% of the light passes through the film, that film has a density of 2; if 0.1% of the illuminator's light passes through the film the density is 3, and so on. (Shephard, p. 102)

47. Which of the following are methods of limiting the production of scattered radiation?
1. Using moderate ratio grids
2. Using the prone position for abdominal examinations
3. Restricting the field size to the smallest practical size
A. 1 and 2 only
B. 1 and 3 only
C. 2 and 3 only
D. 1, 2, and 3

The answer is C.
2. EXPLANATION: 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.

48. Which of the following combinations would pose the most hazard to a particular anode?
a. 0.6 mm focal spot, 75 kVp, 30 mAs
b. 0.6 mm focal spot, 85 kVp, 15 mAs
c. 1.2 mm focal spot, 75 kVp, 30 mAs
d. 1.2 mm focal spot, 85 kVp, 15 mAs

The answer is A.
ii. EXPLANATION: Radiographic rating charts enable the operator to determine the maximum safe mA, exposure time, and kVp for a particular exposure using a particular x-ray tube. An exposure that can be made safely with the large focal spot may not be safe for use with the small focal spot of the same x-ray tube. The total number of HU that an exposure generates also influences the amount of stress (in the form of heat) imparted to the anode. The product of mAs and kVp determines HU. Groups A and C produce 2250 HU; groups B and D produce 1275 HU. Groups B and D deliver less heat load, but group D delivers it to a larger area (actual focal spot) making this the least hazardous group of technical factors.

49. In fluoroscopy, the automatic brightness control is used to adjust the
a. kilovoltage (kVp) and milliamperage (mA)
b. backup timer
c. milliamperage (mA) and time
d. kilovoltage (kV) and time

i. Answer is A
ii. EXPLANATION: As body areas of different thicknesses and densities are scanned with the image intensifier, image brightness and contrast require adjustment. The ABC functions to maintain constant brightness and contrast of the output screen image, correcting for fluctuations in x-ray beam attenuation with adjustments in kilovoltage and/or milliamperage. There are also brightness and contrast controls on the monitor that the radiographer can regulate. (Bushong, 8th ed., p. 358)

2. Which of the following is most useful for bone age evaluation?
a. Lateral skull
b. PA chest
c. AP pelvis
d. PA hand

The answer is D.
ii. EXPLANATION: A PA projection of the left hand and wrist is obtained most often to evaluate skeletal maturation. These images are compared with standard normal images for the age and sex of the child. Additional supplemental images may be requested. (Bontrager and Lampignano, 6th ed., p. 654)

3. X-ray photon energy is inversely related to
i. photon wavelength
ii. applied milliamperes (mA)
iii. applied kilovoltage (kV)
A. 1 only
B. 1 and 2 only
C. 1 and 3 only
D. 1, 2, and 3

The answer is A.
2. EXPLANATION: 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.

6. Demonstration of the posterior fat pad on the lateral projection of the adult elbow can be caused by
i. trauma or other pathology
ii. greater than 90-degree flexion
iii. less than 90-degree flexion
A. 1 only
B. 3 only
C. 1 and 2 only
D. 1 and 3 only

The answer is D.
2. EXPLANATION: There are three important fat pads associated with the elbow, best demonstrated in the true lateral projection. They cannot be demonstrated in the AP projection because of their superimposition on bony structures. The anterior fat pad is located just anterior to the distal humerus. The posterior fat pad is located within the olecranon fossa at the distal posterior humerus. The supinator fat pad/stripe is located at the proximal radius just anterior to the head, neck, and tuberosity. The posterior fat pad is not visible radiographically in the normal elbow. The posterior fat pad is visible in cases or trauma or other pathology and when the elbow is insufficiently flexed.

7. Which of the following factors influence(s) the production of scattered radiation?
i. Kilovoltage level
ii. Tissue density
iii. Size of field
A. 1 only
B. 1 and 2 only
C. 1 and 3 only
D. 1, 2, and 3

The answer is D.
2. EXPLANATION: 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. (Carlton and Adler, 4th ed., p. 228)

8. Which of the following contribute(s) to base-plus fog?
i. Chemical fog
ii. Base tint
iii. Background radiation
A. 1 only
B. 1 and 2 only
C. 1 and 3 only
D. 1, 2, and 3

The answer is D.
2. EXPLANATION: Base-plus fog is the small amount of measurable density on unexposed and processed x-ray film. This fog is a result of environmental background radiation that is present during film manufacture, transportation, and storage. The (usually blue) tint, given the base to enhance contrast, adds more density. Finally, the emulsion receives further fog as the film is chemically processed. Base-plus fog should not exceed 0.2D. (Carlton and Adler, 4th ed., p. 307)

9. During an upper gastrointestinal (GI) examination, a stomach of average shape demonstrates a barium-filled fundus and double contrast of the pylorus and duodenal bulb. The position used is most likely
a. AP erect
b. PA
c. RAO
d. LPO

The answer is D.
ii. EXPLANATION: With the body in the AP recumbent position (or LPO position), barium flows easily into the fundus of the stomach (from the more distal portions of the stomach), displacing/drawing the stomach somewhat superiorly. The fundus, then, is filled with barium, whereas the air that had been in the fundus is now displaced into the gastric body, pylorus, and duodenum, illustrating them in double contrast. Double-contrast delineation of these structures allows us to see through the stomach to the retrogastric areas and structures. The RAO position demonstrates a barium-filled pylorus and duodenum. Anterior and posterior aspects of the stomach are visualized in the lateral position; medial and lateral aspects of the stomach are visualized in the AP projection. (Frank, Long, and Smith, 11th ed., vol. 2, p. 142)

10. All the following statements regarding the use of iodinated contrast agents with patients taking metformin hydrochloride are true except
a. metformin is used to help lower blood sugar levels in type 2 diabetic patients
b. patients on metformin who have intravenous (IV) iodinated contrast agent administration are at risk for renal failure
c. metformin should be withheld for 48 hours before IV iodinated contrast studies
d. metformin should be withheld for 48 hours after IV iodinated contrast studies

The answer is C.
ii. EXPLANATION: Metformin hydrochloride (Glucophage) is used as an adjunct to appropriate diet to lower blood glucose levels in patients who have type 2 diabetes and whose hyperglycemia is not being managed satisfactorily with diet alone. Patients on Glucophage who are having intravascular iodinated contrast studies can develop an acute alteration of renal function or acute acidosis. It is recommended that patients on Metformin hydrochloride (Glucophage) have it withheld 48 hours after the examination

11. The squeegee assembly in an automatic processor
i. functions to remove excess solution from films
ii. is located near the crossover rollers
iii. helps establish the film's rate of travel
A. 1 only
B. 2 only
C. 1 and 2 only
D. 1, 2, and 3

The answer is C.
2. EXPLANATION: An exposed radiographic film contains an invisible (latent) image. Only through processing can this image be converted to a permanent, visible (manifest) image. As the film exits the developer section, it passes through the crossover assembly, and before it enters the fixer section, it passes through the squeegee assembly. The squeegee assembly rollers function to remove excess developer solution from the emulsion before the film enters the fixer. This process helps to maintain fixer strength/activity. The rate of travel through the processor is determined by the transport mechanism, that is, the speed of the rollers as established at time of manufacture. (Shephard, p. 143)

12. Biologic material is most sensitive to radiation exposure under which of the following conditions?
a. Anoxic
b. Hypoxic
c. Oxygenated
d. Deoxygenated

The answer is C.
ii. EXPLANATION: Tissue is most sensitive to radiation exposure when it is in an oxygenated condition. Anoxic refers to a general lack of oxygen in tissue; hypoxic refers to tissue with little oxygen. Anoxic and hypoxic tumors typically are avascular (with little or no blood supply) and, therefore, more radioresistant.

13. The floor of the cranium includes all the following bones except
a. the temporal bones
b. the occipital bone
c. the ethmoid bone
d. the sphenoid bone

The answer is B.
ii. EXPLANATION: The skull is divided into two parts—the cranial bones and the facial bones. There are eight cranial bones. Four of them comprise the calvarium—the frontal, the two parietals, and the occipital. The bones that comprise the floor of the cranium are the two temporals, the ethmoid, and the sphenoid. (Bontrager and Lampignano, 6th ed., p. 368)

14. The function of the developer solution chemicals is to
a. reduce the manifest image to a latent image
b. increase production of silver halide crystals
c. reduce the latent image to a manifest image
d. remove the unexposed crystals from the film

The answer is C.
ii. EXPLANATION: The latent image is the invisible image produced within the film emulsion as a result of exposure to radiation. The developer solution converts this to a visible manifest image. The exposed silver halide grains in the emulsion undergo chemical change in the developer solution, and the unexposed crystals are removed from the film during the fixing process. (Fauber, 2nd ed., p. 163)

15. Which of the following radiographic examinations require(s) the patient to be NPO 8-10 hours prior to examination for proper patient preparation?
i. Abdominal survey
ii. Upper GI series
iii. BE
A. 1 and 2 only
B. 1 and 3 only
C. 2 and 3 only
D. 1, 2, and 3

The answer is C.
2. EXPLANATION: There is no preparation required for an abdominal survey. For an upper GI series and a lower GI series (BE), the patient should be NPO, or have nothing by mouth, for 8 to 10 hours prior to the examination. In addition, a low-residue diet may be imposed, fluid intake may be increased, and cleansing enemas and laxatives may be prescribed to rid the colon of fecal matter.

16. Which of the following combinations will result in the most scattered radiation reaching the image receptor?
a. Using more mAs and compressing the part
b. Using more mAs and a higher ratio grid
c. Using fewer mAs and more kVp
d. Using more mAs and less kVp

The answer is C.
ii. EXPLANATION: As x-ray photons travel through a part, they either pass all the way through to expose the film/image receptor, or they undergo interaction(s) that may result in their being absorbed by the part or deviated in direction. It is those that change direction (scattered radiation) that undermine the image. With respect to the radiographic image, it is responsible for the scattered radiation that reaches the film/image receptor. Scattered radiation adds unwanted, degrading densities to the radiographic image. The single most important way to reduce the production of scattered radiation is to collimate. Although collimation, use of lower kVp (with appropriately higher mAs), and compression can be used, a large amount of scattered radiation is still generated within the part being radiographed and, because it adds unwanted noninformation-carrying densities, it can have a severely degrading effect on image quality, thus the need for grids. (Bushong, 8th ed, p 236)

18. How should the wheelchair footrests be positioned as a patient is assisted into or out of a wheelchair?
a. Accessible to the foot
b. Moved aside
c. Parallel to the floor
d. Available for support

The answer is B.
ii. EXPLANATION: 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. (Adler and Carlton, 4th ed., p. 169)

19. A three-phase timer can be tested for accuracy using a synchronous spinning top. The resulting image looks like a
a. series of dots or dashes, each representative of a radiation pulse
b. solid arc, with the angle (in degrees) representative of the exposure time
c. series of gray tones, from white to black
d. multitude of small, mesh-like squares of uniform sharpness

The answer is B.
ii. EXPLANATION: When a spinning top is used to test the efficiency of a single-phase timer, the result is a series of dots or dashes, with each representing a pulse of radiation. With full-wave-rectified current and a possible 120 dots (pulses) available per second, one should visualize 12 dots at 1/10 s, 24 dots at 1/5 s, 6 dots at 1/20 s, and so on. However, because three-phase equipment is at almost constant potential, a synchronous spinning top must be used, and the result is a solid arc (rather than dots). The number of degrees formed by the arc is measured and equated to a particular exposure time. A multitude of small, mesh-like squares describes a screen contact test. An aluminum step wedge (penetrometer) may be used to demonstrate the effect of kilovoltage on contrast (demonstrating a series of gray tones from white to black), with a greater number of grays demonstrated at higher kilovoltage levels. (Selman, 9th ed., p. 106)

20. Which of the following statements is (are) correct regarding the parietoacanthial projection (Waters' method) of the skull?
i. The head is rested on the extended chin.
ii. The orbitomeatal line (OML) is perpendicular to the (IR).
iii. The maxillary antra should be projected above the petrosa.
A. 1 only
B. 1 and 2 only
C. 1 and 3 only
D. 1, 2, and 3

The answer is C.
2. EXPLANATION: The parietoacanthial projection (Waters' position) of the skull is valuable for the demonstration of facial bones or maxillary sinuses. The head is rested on the extended chin so that the OML forms a 37° angle with the IR. This projects the petrous pyramids below the floor of the maxillary sinuses and provides an oblique frontal view of the facial bones.

21. Which of the following criteria are used to evaluate a PA projection of the chest?
i. Ten posterior ribs should be visualized.
ii. Sternoclavicular joints should be symmetrical.
iii. The scapulae should be lateral to the lung fields.
A. 1 and 2 only
B. 1 and 3 only
C. 2 and 3 only
D. 1, 2, and 3

The answer is D.
2. EXPLANATION: To evaluate sufficient inspiration and lung expansion, 10 posterior ribs should be visualized. The sternoclavicular joints should be symmetrical; any loss of symmetry indicates rotation. To visualize maximum lung area, the shoulders are rolled forward to move the scapulae laterally from the lung fields. (Ballinger & Frank, vol 1, p 527)

22. Which of the following quantities of filtration is most likely to be used in mammography?
a. 0.5 mm Mo
b. 1.5 mm Al
c. 1.5 mm Cu
d. 2.0 mm Cu

The answer is A.
ii. EXPLANATION: Soft tissue radiography requires the use of long-wavelength, low-energy x-ray photons. Very little filtration is used in mammography. Certainly, anything more than 1.0 mm of aluminum would remove the useful soft photons, and the desired high contrast could not be achieved. Dedicated mammographic units usually have molybdenum targets (for the production of soft radiation) and a small amount of molybdenum filtration. (Carlton & Adler, p 581)

23. Tangential axial projections of the patella can be obtained in which of the following positions?
1. supine flexion 45° (Merchant)
2. prone flexion 90° (Settegast)
3. prone flexion 55° (Hughston)
A. 1 only
B. 1 and 2 only
C. 2 and 3 only
D. 1, 2, and 3 only

The answer is D.
2. EXPLANATION: The tangential axial projections of the patella are also often referred to as "sunrise" or "skyline" views. The supine flexion 45° (Merchant) position requires a special apparatus, and the patellae can be examined bilaterally. This position also requires patient comfort without muscle tension—muscle tension can cause a subluxed patella to be pulled into the intercondyler sulcus, giving the appearance of a normal patella. The two prone positions differ according to the degree of flexion employed. The 90° flexion (Settegast) position must not be employed with suspected patellar fracture.

24. Which of the following devices converts electrical energy to mechanical energy?
a. Motor
b. Generator
c. Stator
d. Rotor

The answer is A.
ii. EXPLANATION: A motor is the device used to convert electrical energy to mechanical energy. The stator and rotor are the two principal parts of an induction motor. A generator converts mechanical energy into electrical energy. (Selman, p 78)

25. All the following are related to recorded detail except
a. Milliamperage
b. focal-spot size
c. screen speed
d. OID

The answer is A.
ii. EXPLANATION: The focal-spot size selected will determine the amount of focal-spot, or geometric, blur produced in the image. Different screen speeds will create differing degrees of fluorescent light diffusion, affecting recorded detail. OID is 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. (Selman, 9th ed., pp. 206-210)

26. Another name for Hirschsprung's disease, the most common cause of lower GI obstruction in neonates, is
a. Intussusception
b. Volvulus
c. congenital megacolon
d. pyloric stenosis

The answer is C.
ii. EXPLANATION: 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 the normal, healthy bowel. Hirschsprung disease is diagnosed by BE or, in mild cares, by rectal biopsy. Intussusception is "telescoping" of the bowel, causing (mechanical) obstruction. Volvulus is twisting of the bowel on itself causing (mechanical) obstruction. Pyloric stenosis is a condition of the upper GI tract. (Bontrager and Lampignano, 6th ed., p. 659)

27. Widening of the intercostal spaces is characteristic of which of the following conditions?
a. Pneumothorax
b. Emphysema
c. Pleural effusion
d. Pneumonia

The answer is B.
ii. EXPLANATION: Chest radiographs demonstrating emphysema will show the characteristic irreversible trapping of air that increases gradually and overexpands the lungs. This produces the characteristic "flattening" of the hemidiaphragms and widening of the intercostal spaces. The increased air content of the lungs requires a compensating decrease in technical factors. Pneumonia is inflammation of the lungs, usually caused by bacteria, virus, or chemical irritant. Pneumothorax is a collection of air or gas in the pleural cavity (outside the lungs), with an accompanying collapse of the lung. Pleural effusion is excessive fluid between the parietal and visceral layers of pleura. (Bontrager and Lampignano, 6th ed., p. 92)

28. All the following have an impact on radiographic contrast except
a. photon energy
b. grid ratio
c. OID
d. focal-spot size

The answer is D.
ii. EXPLANATION: 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. (Shephard, p. 203)

29. Accurate operation of the AEC device depends on
1. the thickness and density of the object
2. positioning of the object with respect to the photocell
3. beam restriction
A. 1 only
B. 1 and 2 only
C. 2 and 3 only
D. 1, 2, and 3

The answer is C.
2. EXPLANATION: The AEC automatically terminates the exposure when the proper density has been recorded on the film. The important advantage of the phototimer, then, is that it can accurately duplicate radiographic densities. It is very useful in providing accurate comparison in follow-up examinations and in decreasing patient exposure dose by reducing the number of "retakes" needed because of improper exposure. The AEC automatically adjusts the exposure required for body parts with different thicknesses and densities. However, proper functioning of the phototimer depends on accurate positioning by the radiographer. The correct photocell(s) must be selected, and the anatomic part of interest must completely cover the photocell to achieve the desired density. If collimation is inadequate and a field size larger than the part is used, excessive scattered radiation from the body or tabletop can cause the AEC to terminate the exposure prematurely, resulting in an underexposed radiograph.

30. An exposed image plate will retain its image for about
a. 2 hours
b. 8 hours
c. 24 hours
d. 48 hours

The answer is B.
ii. EXPLANATION: Computed radiography (CR) cassettes use no intensifying screens or film—hence, the term filmless radiography. The cassettes have a protective function (for the image plate within) and can be used in the Bucky tray or directly under the anatomic part; they need not be light-tight because the image plate is not light sensitive. The cassette has a thin lead-foil backing (similar to traditional cassettes) to absorb backscatter. Inside the cassette is the photostimulable phosphor (PSP) image plate, sometimes referred to simply as an image plate (IP). This PSP or IP within the cassette has a layer of europium-activated barium fluorohalide that serves as the IR as 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. (Carlton and Adler, 4th ed., p. 358)

31. Using fixed milliampere-seconds and variable kilovoltage technical factors, each centimeter increase in patient thickness requires what adjustment in kilovoltage?
a. Increase 2 kV
b. Decrease 2 kV
c. Increase 4 kV
d. Decrease 4 kV

The answer is A.
ii. EXPLANATION: 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. (Shephard, pp. 299-300)

32. The radiographer must perform which of the following procedures prior to entering a contact isolation room with a mobile x-ray unit?
1. Put on gown and gloves only.
2. Put on gown, gloves, mask, and cap.
3. Clean the mobile x-ray unit.
A. 1 only
B. 2 only
C. 1 and 3 only
D. 2 and 3 only

The answer is A.
2. EXPLANATION: When performing bedside radiography in a contact isolation room, the radiographer should wear a gown and gloves. The cassettes 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.

33. A type of cancerous bone tumor occurring in children and young adults and arising from bone marrow is
a. Ewing sarcoma
b. multiple myeloma
c. Enchondroma
d. osteochondroma

The answer is A.
ii. EXPLANATION: Ewing sarcoma is a (primary) malignant bone tumor that arises from bone marrow and occurs in children and young adults. The disease is characterized by new bone formation in a layering effect—giving the bone the characteristic "onion peel" appearance radiographically. Multiple myeloma is also a cancerous bone tumor usually affecting adults between the ages of 40 and 70 years. Bone undergoes osteolytic changes, and radiographic demonstration appears as circular areas of bone loss. As their name implies (chondr), enchondroma and osteochondroma involve cartilage—they are both benign conditions

34. A controlled area is defined as one
1. that is occupied by people trained in radiation safety
2. that is occupied by people who wear radiation monitors
3. whose occupancy factor is 1
A. 1 and 2 only
B. 2 only
C. 1 and 3 only
D. 1, 2, and 3

The answer is D.
2. EXPLANATION: 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. (Bushong, 9th ed., p. 586)

35. How much protection is provided from a 100-kVp x-ray beam when using a 0.50-mm lead-equivalent apron?
a. 40%
b. 75%
c. 88%
d. 99%

The answer is B.
ii. EXPLANATION: 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. (Thompson et al., p. 457)

36. Which interaction between x-ray photons and matter involves partial transfer of the incident photon energy to the involved atom?
a. Photoelectric effect
b. Compton scattering
c. Coherent scattering
d. Pair production

The answer is B.
ii. EXPLANATION: The photoelectric effect and Compton scattering are the two predominant interactions between x-ray photons and matter in diagnostic x-ray. In Compton scatter, the high-energy incident photon uses only part of its energy to eject an outer-shell electron. It retains most of its original energy in the form of a scattered x-ray. The outer-shell electron leaves the atom and is called a recoil electron. Compton scatter is the interaction between x-ray photons and matter that occurs most frequently in diagnostic x-ray and is the major contributor of scattered radiation fog. In the photoelectric effect, the low-energy incident photon uses all its energy to eject an atom's inner-shell electron. When photon ceases to exist, it means it has used all its energy to ionize the atom. The part has absorbed the x-ray photon. This interaction contributes to patient dose and produces short-scale contrast. (Bushong, 8th ed., pp. 176-177)

37. The AP oblique projection (medial rotation) of the elbow demonstrates which of the following?
1. Radial head free of superimposition
2. Olecranon process within the olecranon fossa
3. Coronoid process free of superimposition
A. 1 only
B. 1 and 2 only
C. 2 and 3 only
D. 1, 2, and 3

The answer is C.
2. EXPLANATION: The AP oblique projection (medial rotation) of the elbow superimposes the radial head and neck on the proximal ulna. It demonstrates the olecranon process within the olecranon fossa, and it projects the coronoid process free of superimposition. The radial head is projected free of superimposition in the AP oblique projection (lateral rotation) of the elbow. (Saia, p 10)

38. Changes in milliampere-seconds can affect all the following except
a. quantity of x-ray photons produced
b. exposure rate
c. optical density
d. recorded detail

The answer is D.
ii. EXPLANATION: 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. (Shephard, p. 170)

39. What are the effects of scattered radiation on a radiographic image?
a. It produces fog.
b. It increases contrast.
c. It increases grid cutoff.
i. 1 only
ii. 2 only
iii. 1 and 2 only
iv. 1, 2, and 3

The answer is A.
2. EXPLANATION: 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. (Bushong, 8th ed., p. 248)

40. Which of the following technical changes would best serve to remedy the effect of very dissimilar tissue densities?
a. Use of high-speed screens
b. Use of a high-ratio grid
c. High-kilovoltage exposure factors
d. High milliampere-seconds exposure factors

The answer is C.
ii. EXPLANATION: 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. Radiographic contrast generally increases with an increase in screen speed. The higher the grid ratio, the higher is the contrast. Exposure factors using high milliampere-seconds generally result in excessive image density, frequently obliterating much of the gray scale. (Bushong, 8th ed., p. 273; Shephard, p. 200)

41. Which of the following causes pitting, or many small surface melts, of the anode's focal track?
a. Vaporized tungsten on the glass envelope
b. Loss of anode rotation
c. A large amount of heat to a cold anode
d. Repeated, frequent overloading

The answer is D.
ii. EXPLANATION: As the filament ages, vaporized tungsten may be deposited on the port window and act as an additional filter. Tungsten may also vaporize as a result of anode abuse. Exposures in excess of safe values deliver sufficient heat to cause surface melts, or pits, on the focal track. This results in roughening of the anode surface and decreased tube output. Delivery of a large amount of heat to a cold anode can cause cracking if the anode does not have sufficient time to disperse the heat. Loss of anode rotation would cause one large melt on the focal track because the electrons would bombard only one small area. If the anode is not heard to be rotating, the radiographer should not make an exposure. (Selman, 9th ed., pp. 137-138)

42. Which of the following precautions should be observed when radiographing a patient who has sustained a traumatic injury to the hip?
1. When a fracture is suspected, manipulation of the affected extremity should be performed by a physician.
2. The axiolateral projection should be avoided.
3. To evaluate the entire region, the pelvis typically is included in the initial examination.
A. 1 only
B. 1 and 3 only
C. 2 and 3 only
D. 1, 2, and 3

The answer is B.
2. EXPLANATION: Typically, traumatic injury to the hip requires a cross-table (axiolateral) lateral projection, as well as an AP projection of the entire pelvis. Both of these are performed using minimal manipulation of the affected extremity, reducing the possibility of further injury. A physician should perform any required manipulation of the traumatized hip.

43. Which of the following projections of the elbow should demonstrate the coronoid process free of superimposition and the olecranon process within the olecranon fossa?
a. AP
b. Lateral
c. Medial oblique
d. Lateral oblique

The answer is C.
ii. EXPLANATION: On the AP projection of the elbow, the radial head and ulna are normally somewhat superimposed. The lateral oblique demonstrates the radial head free of ulnar superimposition. The lateral projection demonstrates the olecranon process in profile. The medial oblique demonstrates considerable overlap of the proximal radius and ulna, but should clearly demonstrate the coronoid process free of superimposition and the olecranon process within the olecranon fossa. (Saia, p 96)

44. Recorded detail is directly related to
1. source-image distance (SID).
2. tube current.
3. focal spot size.
A. 1 only
B. 1 and 2 only
C. 2 and 3 only
D. 1, 2, and 3

The answer is A.
2. EXPLANATION: As SID increases, so does recorded detail, because magnification is decreased. Therefore, SID is directly related to recorded detail. As focal spot size increases, recorded detail decreases because more penumbra is produced. Focal spot size is thus inversely related to radiographic sharpness or recorded detail. Tube current affects radiographic density and is unrelated to recorded detail.

45. With milliamperes (mA) increased to maintain output intensity, how is the ESE affected as the source-to-skin distance (SSD) is increased?
a. The ESE increases
b. The ESE decreases
c. The ESE remains unchanged
d. ESE is unrelated to SSD

The answer is B.
ii. EXPLANATION: Because of the divergent quality of the x-ray beam, as source-to-image receptor distance (SSD) increases, entrance skin exposure (ESE) decreases. SSD must be at least 12 inches on mobile fluoroscopic equipment, and at least 15 inches on fixed fluoroscopic equipment. (Bushong, 9th ed., p. 582)

46. According to the CDC, all the following precaution guidelines are true except
a. airborne precautions require that the patient wear a mask
b. masks are indicated when caring for patients on MRSA precautions
c. patients under MRSA precautions require a negative-pressure room
d. gloves are indicated when caring for a patient on droplet precautions

The answer is C.
ii. EXPLANATION: 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 methicillin-resistant Staphylococcus aureus (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.

47. Which of the following could be used to improve recorded detail?
1. Slower screen/film combination
2. Smaller focal-spot size
3. Correct photocell selection
A. 1 only
B. 1 and 2 only
C. 2 and 3 only
D. 1, 2, and 3

The answer is B.
2. EXPLANATION: The factors that affect the recorded detail of traditional screen/film imaging are focal spot size, source-to-image distance (SID), object-to-image distance (OID), film/screen speed, and motion. Recorded detail is improved using small focal-spot size, largest practical SID, shortest possible OID, and slowest practical screen/film combination and avoiding motion of the part being imaged. Other imaging factors such as milliampere-seconds and kilovoltage selection and correct photocell selection influence the visibility of recorded detail by affecting density and contrast.

48. An RT (ARRT) is supervising manager of a short-staffed imaging facility in a state requiring certification. An applicant arrives whose ARRT certification has lapsed. The manager hires him to fill a 20-hour position doing chest and extremity radiography. The supervisor is guilty of
a. breaking the ARRT Code of Ethics
b. breaking the ARRT Rules of Ethics
c. malpractice
d. nothing, because position responsibilities are limited

The answer is B.
ii. EXPLANATION: The ARRT Standards of Ethics apply to those Registered Technologists holding ARRT certification and Candidates for ARRT certification. The Standards consist of two parts: the Code of Ethics (aspirational) and the Rules of Ethics (mandatory). The ARRT Rules of Ethics are mandatory minimum professional standards for all RTs and candidate RTs. Violators, and individuals who permit violation, of these Rules are subject to sanctions. Rules of Ethics numbers 15 and 21 specifically refer to those who knowingly assist another without proper certification to engage in the practice of radiologic technology, and/or those who fail to promptly report such activity to the ARRT—as being subject to sanction. (ARRT Standards of Ethics)

49. The steeper the straight-line portion of a characteristic curve for a particular film, the
1. slower is the film speed
2. higher is the film contrast
3. greater is the exposure latitude
A. 1 only
B. 2 only
C. 2 and 3 only
D. 1, 2, and 3

The answer is B.
2. EXPLANATION: The steepness of the characteristic curve is representative of image contrast. The steeper the curve, the greater is the density difference and the higher is the contrast. The speed of the film is determined by the curve's position on the log-relative scale: When comparing two or more characteristic curves, the faster film lies farthest to the left. The faster the film speed, the less is the exposure latitude. (Shephard, p. 105)

51. Which section of the automatic processor shown in Figure 6-9 is associated with preservation of the x-ray image?
a. Section 1
b. Section 2
c. Section 3
d. Section 4

The answer is C.
ii. EXPLANATION: As the exposed film enters the processor from the feed tray, it first enters the developer section (number 1), where exposed silver bromide crystals are reduced to black metallic silver. The film then enters the fixer (number 2), where the unexposed silver grains are removed from the film by the clearing agent. The film then enters the wash section (number 3), where chemicals are removed from the film to preserve the image, improving archival quality. From the wash, the film enters the dryer section (number 4). (Selman, 9th ed., p. 194)

52. Which blood vessels are best suited for determination of pulse rate?
a. Superficial arteries
b. Deep arteries
c. Superficial veins
d. Deep veins

The answer is A.
ii. EXPLANATION: 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. (Adler and Carlton, 4th ed., p. 198)

53. The symbols 130/56Ba and 138/56Ba are examples of which of the following?
a. Isotopes
b. Isobars
c. Isotones
d. Isomers

The answer is A.
ii. EXPLANATION: Ba and Ba are isotopes of the same element, barium (Ba), because they have the same atomic number but different mass numbers (numbers of neutrons). Isobars are atoms with the same mass number but different atomic numbers. Isotones have the same number of neutrons but different atomic numbers. Isomers have the same atomic number and mass number; they are identical atoms existing at different energy states. (Bushong, 8th ed., p. 49)

54. During measurement of blood pressure, which of the following occurs as the radiographer controls arterial tension with the sphygmomanometer?
a. The brachial vein is collapsed
b. The brachial artery is temporarily collapsed
c. The antecubital vein is monitored
d. Oxygen saturation of arterial blood is monitored

The answer is B.
ii. EXPLANATION: A stethoscope and a sphygmomanometer are used together to measure blood pressure. The sphygmomanometer's cuff is placed around the midportion of the upper arm. The cuff is inflated to a value higher than the patient's systolic pressure to temporarily collapse the brachial artery. As the inflation is gradually released, the first sound heard is the systolic pressure; the normal range is 110 to 140 mmHg. When no more sound is heard, the diastolic pressure is recorded. The normal diastolic range is 60 to 90 mm Hg. Elevated blood pressure is called hypertension. Hypotension, low blood pressure, is not of concern unless it is caused by injury or disease; in that case, it can result in shock. (Adler and Carlton, 4th ed., pp. 200-201)

55. During CR imaging, the latent image present on the PSP is changed to a computerized image by the
a. PSP
b. Scanner-reader
c. ADC
d. helium-neon laser

The answer is C.
ii. EXPLANATION: 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. (Carlton and Adler, 4th ed., p. 358)

56. Continuous rotation of the CT x-ray tube and detector array, with simultaneous movement of the CT couch, has been accomplished through implementation of
a. additional cables
b. slip rings
c. multiple rows of detectors
d. electron beam CT

The answer is B.
ii. EXPLANATION: In the 1990s, the implementation of slip ring technology allowed continuous rotation of the x-ray tube (through elimination of cables) and simultaneous couch movement. Sixth-generation CT scanning is termed helical (or spiral) CT—permitting acquisition of volume multislice scanning. Today's helical multislice scanners, employing thousands of detectors (up to 60+ rows), can obtain uninterrupted data acquisition of 128 "slices" per tube rotation and can perform 3D multiplanar reformation (MPR). Fifth-generation CT is electron beam; ultra high-speed CT is used specifically for cardiac imaging. (Bushong, 9th ed., p. 375; Romans, pp. 50-51)

57. Which of the following should be performed to rule out subluxation or fracture of the cervical spine?
a. Oblique cervical spine, seated
b. AP cervical spine, recumbent
c. Horizontal beam lateral
d. Laterals in flexion and extension

The answer is C.
ii. EXPLANATION: When a cervical spine radiograph is requested to rule out subluxation or fracture, the patient will arrive in the radiology area on a stretcher. The patient should not be moved before a subluxation is ruled out. Any movement of the head and neck could cause serious damage to the spinal cord. A horizontal beam lateral projection is performed and evaluated. The physician then will decide what further images are required. (Frank, Long, and Smith, 11th ed., vol. 2, p. 35)

58. For the average patient, the CR for a lateral projection of a barium-filled stomach should enter
a. midway between the midcoronal line and the anterior abdominal surface
b. midway between the vertebral column and the lateral border of the abdomen
c. at the midcoronal line at the level of the iliac crest
d. perpendicular to the level of L2

The answer is A.
ii. EXPLANATION: Lateral projections of the barium-filled stomach (Figure 2-61) may be performed recumbent or upright for demonstration of the retrogastric space. With the patient in the (usually right) lateral position, the CR is directed to a point midway between the midcoronal line and the anterior surface of the abdomen at the level of L1. When the patient is in the LPO or RAO position, the CR should be directed midway between the vertebral column and the lateral border of the abdomen. For the PA projection, the CR is directed perpendicular to the IR at the level of L2. (Frank, Long, and Smith, 11th ed., vol. 2, pp. 152-153)

59. Which of the following will influence recorded detail?
1. Screen speed
2. Screen-film contact
3. Focal spot
A. 1 and 2 only
B. 1 and 3 only
C. 2 and 3 only
D. 1, 2, and 3

The answer is D.
2. EXPLANATION: The faster the imaging system, the greater is the sacrifice of image clarity (recorded detail). As intensifying-screen speed increases, recorded detail decreases. Perfect screen-film contact is essential for good detail. Any areas of poor contact result in considerable blurriness in the radiographic image. Focal-spot blur is related to focal-spot size; smaller focal spots produce less blur and thus better recorded detail. (Selman, 9th ed., pp. 206-210)

60. The roentgen is the unit of
a. radiation dose
b. biologic dose
c. dose equivalent
d. ionization in air

The answer is D.
ii. EXPLANATION: There are several radiation units that are used to express quantity and effects of radiation. Rad (radiation absorbed dose) expresses energy deposited (as a result of ionizations) in any kind of absorber. The unit of exposure, the roentgen, is used to express the quantity of ionization in air. The unit of dose equivalent is the rem (radiation equivalent man), which expresses dose to biologic material. (Selman, 9th ed., p. 131)

61. If a radiograph exhibits insufficient density, this might be attributed to
1. inadequate kVp.
2. inadequate SID.
3. grid cutoff.
A. 1 only
B. 1 and 2 only
C. 1 and 3 only
D. 1, 2, and 3

The answer is C.
2. EXPLANATION: As kVp 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. (Selman, pp 214, 240-242)

62. The image intensifier's input phosphor differs from the output phosphor in that the input phosphor
a. is much larger than the output phosphor
b. emits electrons, whereas the output phosphor emits light photons
c. absorbs electrons, whereas the output phosphor absorbs light photons
d. is a fixed size, and the size of the output phosphor can vary

The answer is A.
ii. EXPLANATION: The image intensifier's input phosphor is 6 to 9 times larger than the output phosphor. It receives the remnant radiation emerging from the patient and converts it into a fluorescent light image. Very close to the input phosphor, separated only by a thin, transparent layer, is the photocathode. The photocathode is made of a photoemissive alloy, usually a cesium and antimony compound. The fluorescent light image strikes the photocathode and is converted to an electron image, which is focused by the electrostatic lenses to the small output phosphor. (Bushong, 8th ed., pp. 360-363)

63. Radiographs from a particular three-phase, full-wave-rectified x-ray unit, made using known correct exposures, were underexposed. A synchronous spinning top test was performed using 200 mA, 1/12 second, and 70 kVp, and a 20° arc is observed on the test film. Which of the following is most likely the problem?
a. The 1/12-second time station is inaccurate
b. The 200-mA station is inaccurate
c. A rectifier is not functioning
d. The processor needs servicing

The answer is A.
ii. EXPLANATION: A synchronous spinning top test is used to test timer accuracy or rectifier function in three-phase equipment. Because three-phase, full-wave-rectified current would expose a 360° arc each second, a 1/12-second exposure should expose a 30° arc. Anything more or less indicates timer inaccuracy. If exactly one half of the expected arc appears, one should suspect rectifier failure. (Saia, p 434)

64. Possible side effects of an iodinated contrast medium that is administered intravenously include all the following except
1. warm, flushed feeling.
2. altered taste.
3. rash and hives.
A. 1 only
B. 3 only
C. 2 and 3 only
D. 1, 2, and 3

. The answer is B.
2. EXPLANATION: 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. (Adler and Carlton, 4th ed., p. 279)

65. Which of the following is most likely to occur as a result of using a 30-in. SID with a 14 x 17 in. IR to radiograph a fairly homogeneous structure?
a. Production of quantum mottle
b. Density variation between opposite ends of the IR
c. Production of scatter radiation fog
d. Excessively short-scale contrast

The answer is B.
ii. EXPLANATION: Since x-ray photons are produced at the tungsten target, they more readily diverge toward the cathode end of the x-ray tube. As they try to diverge toward the anode, they interact with and are absorbed by the anode "heel." Consequently, there is a greater intensity of x-ray photons at the cathode end of the x-ray beam. This phenomenon is known as the anode heel effect. Because shorter SIDs and larger IR sizes require greater divergence of the x-ray beam to provide coverage, the anode heel effect will be accentuated.

66. How much protection is provided from a 75-kVp x-ray beam when using a 0.50-mm lead equivalent apron?
a. 51%
b. 66%
c. 88%
d. 99%

The answer is C.
ii. EXPLANATION: 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 are the most common. The 1.0-mm lead equivalent apron will provide close to 100% protection at most kVp 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. (Thompson et al, p 457)

67. If a radiograph were made of an average-size knee using automatic exposure control (AEC) and all three photocells were selected, the resulting radiograph would demonstrate
a. excessive density
b. insufficient density
c. poor detail
d. adequate exposure

The answer is B.
ii. EXPLANATION: Proper functioning of the photo timer depends on accurate positioning by the radiographer. The correct photocell(s) must be selected, and the anatomic part of interest must completely cover the photocell(s) to achieve the desired density. If a photocell is left uncovered, scattered radiation from the part being examined will cause premature termination of exposure and an underexposed radiograph.

68. If a radiograph were made of an average-size knee using automatic exposure control (AEC) and all three photocells were selected, the resulting radiograph would demonstrate
a. excessive density
b. insufficient density
c. poor detail
d. adequate exposure

The answer is B.
ii. EXPLANATION: Proper functioning of the photo timer depends on accurate positioning by the radiographer. The correct photocell(s) must be selected, and the anatomic part of interest must completely cover the photocell(s) to achieve the desired density. If a photocell is left uncovered, scattered radiation from the part being examined will cause premature termination of exposure and an underexposed radiograph.

69. The condition that results from a persistent fetal foramen ovale is
a. an atrial septal defect
b. a ventricular septal defect
c. a patent ductus arteriosus
d. coarctation of the aorta

The answer is A.
ii. EXPLANATION: 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. 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. (Tortora and Derrickson, 11th ed., p. 794)

70. Which of the following is the factor of choice for the regulation of radiographic (optical) density?
a. kVp
b. mAs
c. SID
d. Filtration

. The answer is B.
ii. EXPLANATION: The principal quantitative factor regulating radiographic (or optical) density is mAs. The mAs selected is directly proportional to radiographic density (ie, if the mAs is cut in half, radiographic density will be halved). Although SID affects exposure rate (according to the inverse square law of radiation), and therefore affects density (according to the density maintenance formula), it is not used to regulate radiographic density. According to the 15% rule, kVp may be used to change radiographic density, but kVp is not a major quantitative factor. The principal use of filtration is to decrease patient skin dose; filtration of that sort will not affect the radiographic image. (Shephard, p 170)

71. The annual dose limit for medical imaging personnel includes radiation from
1. occupational exposure
2. background radiation
3. medical x-rays
A. 1 only
B. 1 and 2 only
C. 2 and 3 only
D. 1, 2, and 3

The answer is A.
2. EXPLANATION: 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. (Thompson et al., p. 459)

72. Which of the following sinus groups is demonstrated with the patient positioned as for a parietoacanthal projection (Waters method) with the CR directed through the patient's open mouth?
a. Frontal
b. Ethmoidal
c. Maxillary
d. Sphenoidal

The answer is D.
ii. EXPLANATION: This is a modification of the parietoacanthal projection (Waters method) in which the patient is requested to open the mouth, and then the skull is positioned so that the OML forms a 37-degree angle with the IR. The CR is directed through the sphenoidal sinuses and exits the open mouth. The routine parietoacanthal projection (with mouth closed) is used to demonstrate the maxillary sinuses projected above the petrous pyramids. The frontal and ethmoidal sinuses are best visualized in the PA axial position (modified Caldwell method). (Bontrager and Lampignano, 6th ed., p. 442)

73. What should be done to correct for magnification when using air-gap technique?
a. Decrease OID
b. Increase OID
c. Decrease SID
d. Increase SID

. The answer is D.
ii. EXPLANATION: OID is used to effect an increase in contrast in the absence of a grid, usually in chest radiography. If a 6-in. air gap (OID) is introduced between the part and the IR, much of the scattered radiation emitted from the body will not reach the IR; thus, the OID acts as a low-ratio grid and increases image contrast. However, the 6-in. OID air gap will make a very noticeable increase in magnification. To correct for this, the SID must be increased. Generally speaking, the SID needs to be increased 7 in. for every 1 in. of OID. With a 6-in. OID, the SID usually is increased from 6 to 10 ft (120 in.). (Shephard, pp. 263, 264)

74. Which of the following is a major cause of bowel obstruction in children?
a. Appendicitis
b. Intussusception
c. Regional enteritis
d. Ulcerative colitis

The answer is B.
ii. EXPLANATION: Intussusception is the telescoping of one part of the intestinal tract into another. It is a major cause of bowel obstruction in children, usually in the region of the ileocecal valve, and is much less common in adults. Radiographically, intussusception appears as the classic "coil spring," with barium trapped between folds of the telescoped bowel. The diagnostic BE procedure occasionally can reduce the intussusception, although care must be taken to avoid perforation of the bowel. Appendicitis occurs when an obstructed appendix becomes inflamed. Distension of the appendix occurs, and if the appendix is left untended, gangrene and perforation can result. Regional enteritis (Crohn disease) is a chronic granulomatous inflammatory disorder that can affect any part of the GI tract but generally involves the area of the terminal ilium. Ulceration and formation of fistulous tracts often occur. Ulcerative colitis occurs most often in young adults; its etiology is unknown, although psychogenic or autoimmune factors seem to be involved. (Bontrager and Lampignano, 6th ed., p. 119)

75. How would the introduction of a 6-in. OID affect image contrast?
a. Contrast would be increased
b. Contrast would be decreased
c. Contrast would not change
d. The scale of contrast would not change

The answer is A.
ii. EXPLANATION: OID can affect contrast when it is used as an air gap. If a 6-in. air gap (OID) is introduced between the part and IR, much of the scattered radiation emitted from the body will not reach the IR, as shown in Figure 7-20. The OID thus is acting as a low-ratio grid and increasing image contrast. (Shephard, p. 205)

76. An AP oblique (lateral rotation) of the elbow demonstrates which of the following?
1. Radial head free of superimposition
2. Capitulum of the humerus
3. Olecranon process within the olecranon fossa
A. 1 only
B. 1 and 2 only
C. 2 and 3 only
D. 1, 2, and 3

The answer is B.
2. EXPLANATION: The radial head and neck are projected free of superimposition in the AP oblique projection (lateral rotation) of the elbow. The humeral capitulum is also well demonstrated in this external oblique position. The AP oblique projection (medial rotation) of the elbow superimposes the radial head and neck on the proximal ulna. It demonstrates the olecranon process within the olecranon fossa, and it projects the coronoid process free of superimposition. (Bontrager and Lampignano, 6th ed., p. 171)

77. A 15% increase in kVp accompanied by a 50% decrease in mAs will result in a(n)
a. shorter scale of contrast
b. increase in exposure latitude
c. increase in radiographic density
d. decrease in recorded detail

The answer is B.
ii. EXPLANATION: A 15% increase in kVp with a 50% decrease in mAs serves to produce a radiograph similar to the original, but with some obvious differences. The overall blackness (radiographic density) is cut in half because of the decrease in mAs. However, the loss of blackness is compensated for by the addition of grays (therefore, longer-scale contrast) from the increased kVp. The increase in kVp also increases exposure latitude; there is a greater margin for error in higher kVp ranges. Recorded detail is unaffected by changes in kVp. (Fauber, pp 59-60)

78. The sensitometric curve may be used to
1. identify automatic processing problems
2. determine film sensitivity
3. illustrate screen speed
A. 1 only
B. 1 and 2 only
C. 2 and 3 only
D. 1, 2, and 3

The answer is B.
2. EXPLANATION: The sensitometric, or characteristic, curve is used to illustrate the relationship between the exposure, given the film and the resulting film density. It can be used to predict a particular film emulsion's response (i.e., speed and sensitivity) by determining how long it takes to record a particular density. The sensitometric curve is used in sensitometry to monitor automatic processing efficiency and consistency. A film is given a series of predetermined exposures and processed. The resulting densities are plotted, and the resulting curve is compared with a known correct curve. Any deviation between the two may indicate processing difficulties. The sensitometric curve illustrates the effects of exposure and processing on radiographic film emulsion; it is unrelated to film speed. (Shephard, pp. 104-108)

79. An unexposed and processed film will have a density of about
a. Zero
b. 0.1
c. 1.0
d. 2.5

The answer is B.
ii. EXPLANATION: Film that is unexposed and has been processed will not be completely clear. The blue-tinted base contributes a small measure of density. A small but measurable amount of exposure from background radiation also can be present, and processing itself produces a small amount of density from chemical fog. Together, this is expressed as base-plus fog and should never exceed a density of 0.2. (Fauber, p. 198)

80. Cells concerned with the formation and repair of bone are
a. Osteoblasts
b. Osteoclasts
c. Osteomas
d. Osteons

The answer is A.
ii. EXPLANATION: Osteoblasts are cells of mesodermal origin that are concerned with formation and repair of bone. Osteoclasts are cells concerned with the breakdown and resorption of old or dead bone. An osteoma is a benign bony tumor. An osteon is the microscopic unit of compact bone, consisting of a haversian canal and its surrounding lamellae. (Bontrager, p 745)

81. In general, as the intensification factor increases,
1. radiographic density increases
2. screen resolution increases
3. recorded detail increases
A. 1 only
B. 1 and 2 only
C. 2 and 3 only
D. 1, 2, and 3

The answer is A.
2. EXPLANATION: Factors that contribute to an increase in the intensification factor generally function to reduce resolution. Slow-speed (detail or "extremity") screens resolve more line pairs per millimeter (lp/mm) than much faster screens. The use of fast screens results in some loss of recorded detail. As intensification factor increases, radiographic density generally increases.

82. In which type of monitoring device do photons release electrons by their interaction with air?
a. Film badge
b. TLD
c. Pocket dosimeter
d. OSL dosimeter

The answer is C.
ii. EXPLANATION: 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. (Selman, 9th ed., p. 400)

83. An advantage of coupling the image intensifier to the TV camera or CCD via a fiber-optic coupling device is its
1. compact size
2. durability
3. ability to accommodate auxilary imaging devices
A. 1 only
B. 1 and 2 only
C. 1 and 3 only
D. 1, 2, and 3

The answer is B.
2. EXPLANATION: The image intensifier can be coupled to the TV camera via a fiber-optic bundle or via a lens coupling device. The fiber-optic connection offers less fragility, more compactness, and ease of maneuverability. The big advantage of the objective lens is that it allows the use of auxiliary imaging devices such as a cine camera or spot-film camera.(Bushong, 8th ed., p. 366)

84. 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)?
1. Use of close collimation
2. Use of low mAs
3. Use of a low-ratio grid
A. 1 only
B. 1 and 2 only
C. 1 and 3 only
D. 1, 2, and 3

The answer is A.
2. EXPLANATION: 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. (Shephard, p. 203)

87. The National Council on Radiation Protection and Measurements (NCRP) has recommended what total equivalent dose limit to the embryo/fetus?
a. 0.5 mSv
b. 5.0 mSv
c. 50 mSv
d. 500 mSv

The answer is B.
ii. EXPLANATION: The NCRP recommends a total equivalent dose limit to the embryo/fetus of 5 mSv (500 mrem, 0.5 rem). This dose limit is the total for the entire gestational period. The dose limit for 1 month during pregnancy is 0.5 mSv (50 mrem, 0.05 rem). (Bushong, 8th ed., p. 557)

88. Indirect modes of disease transmission include
1. airborne
2. fomite
3. vector
A. 1 only
B. 1 and 2 only
C. 1 and 3 only
D. 1, 2, and 3

The answer is D.
2. EXPLANATION: Airborne, fomite, and vector are all indirect modes of transmitting microorganisms. Direct contact involves actual touching of the infected person. A fomite is an inanimate object that has been in contact with an infectious microorganism (e.g., doorknobs or x-ray tables). Although an inanimate object may serve as a temporary host for microbes, microbes flourish on and in the human host, where plenty of body fluids and tissues nourish and feed them. A vector is an animal host of an infectious organism that transmits the infection via a bite or sting, such as the mosquito or deer tick. Airborne contamination occurs via droplets (sneeze) or dust. (Adler and Carlton, 4th ed., pp. 225-226)

89. What is the relationship between kV and HVL?
a. As kV increases, the HVL increases.
b. As kV decreases, the HVL decreases.
c. If the kV is doubled, the HVL doubles.
d. If the kV is doubled, the HVL is squared.

The answer is A.
ii. EXPLANATION: The HVL of a particular beam is defined as that thickness of a material that will reduce the exposure rate to one-half of its original value. The more energetic the beam (the higher the kilovoltage), the greater is the HVL thickness required to cut its intensity in half. Therefore, it may be stated that kilovoltage and HVL have a direct relationship: As kilovoltage increases, HVL increases. (Selman, 9th ed., pp. 122-123)

90. Greater latitude is available to the radiographer when using
1. high-kilovoltage factors.
2. a slow film-screen combination.
3. a high-ratio grid.
A. 1 only
B. 1 and 2 only
C. 2 and 3 only
D. 1, 2, and 3

The answer is B.
2. EXPLANATION: In the low-kilovoltage ranges, a difference of just a few kilovolts makes a very noticeable radiographic difference; that is, there is little latitude. High-kilovoltage techniques offer a much greater margin for error, as do slower film-screen combinations. Grid ratio is unrelated to exposure latitude, but higher-ratio grids offer less tube-centering latitude (i.e., leeway, margin for error) than low-ratio grids. (Carlton and Adler, 4th ed., p. 185)

91. Which of the following factors impact(s) recorded detail?
1. Focal-spot size
2. Subject motion
3. SOD
A. 1 and 2 only
B. 1 and 3 only
C. 2 and 3 only
D. 1, 2, and 3

The answer is D.
2. EXPLANATION: 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.

92. Graves disease is associated with
a. thyroid underactivity
b. thyroid overactivity
c. adrenal underactivity
d. adrenal overactivity

The answer is B.
ii. EXPLANATION: Graves disease is the most frequently occurring form of hyperthyroidism. Graves disease is an autoimmune disorder whose symptoms include enlargement of the thyroid gland and exophthalmos (protrusion of the eyes resulting from fluid buildup behind them). Hypothyroidism can result in cretinism in the child and myxedema in the adult. Adrenal overactivity produces Cushing syndrome; underactivity causes Addison disease. (Tortora and Derrickson, 11th ed., p. 659)

93. Which unit of exposure is described as 100 ergs of energy per gram of irradiated absorber?
a. roentgen
b. rad
c. rem
d. curie

The answer is B.
ii. EXPLANATION: Rad is an acronym for radiation absorbed dose; it measures the energy deposited in any material; that is, it is equal to 100 ergs of energy per gram of any absorber. Roentgen is the unit of exposure; it measures the quantity of ionizations in air. Rem is an acronym for radiation equivalent man; it includes the RBE specific to the tissue irradiated and therefore is a valid unit of measurement for the dose to biologic tissue.

94. The drug acetaminophen is classified as a(n)
a. diuretic
b. antipyretic
c. antihistamine
d. emetic

. The answer is B.
ii. EXPLANATION: An antipyretic is used to reduce fever. Tylenol (acetaminophen) is an example of an antipyretic. An antihistamine is used to relieve allergic effects. Benadryl (diphenhydramine hydrochloride) is an example of an antihistamine that is often on hand in radiology departments in the event of a minor reaction to contrast media. Ipecac is a medication used to induce vomiting and is classified as an emetic. This is easy to remember if you think of what an emesis basin is for. A diuretic is a medication that stimulates the production of urine. Lasix (furosemide) is an example of a diuretic. (Adler and Carlton, 4th ed., p. 265)

96. The total number of x-ray photons produced at the target is contingent on the
1. tube current
2. target material
3. square of the kilovoltage
A. 1 only
B. 1 and 2 only
C. 2 and 3 only
D. 1, 2, and 3

The answer is D.
2. EXPLANATION: The greater the number of electrons making up the electron stream and bombarding the target, the greater is the number of x-ray photons produced. Although kilovoltage usually is associated with the energy of the x-ray photons because a greater number of more energetic electrons will produce more x-ray photons, an increase in kilovoltage will also increase the number of photons produced. Specifically, the quantity of radiation produced increases as the square of the kilovoltage. The material composition of the tube target also plays an important role in the number of x-ray photons produced. The higher the atomic number, the denser and more closely packed are the atoms making up the material, and therefore, the greater is the chance of an interaction between a high-speed electron and the target material. (Selman, 9th ed., pp. 112-115)

97. Grid cutoff due to off-centering would result in
a. overall loss of density
b. both sides of the image being underexposed
c. overexposure under the anode end
d. underexposure under the anode end

The answer is A.
ii. EXPLANATION: 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. (Carlton and Adler, 4th ed., p. 257)

98. An exposure was made at a 36-in. SID using 12 mAs and 75 kVp with a 400-speed imaging system and an 8:1 grid. A second radiograph is requested with improved recorded detail. Which of the following groups of technical factors will best accomplish this task?
a. 15 mAs, 12:1 grid, 75 kVp, 400-speed system, 36-in. SID
b. 15 mAs, 12:1 grid, 75 kVp, 400-speed system, 40-in. SID
c. 30 mAs, 12:1 grid, 75 kVp, 200-speed system, 40-in. SID
d. 12 mAs, 8:1 grid, 86 kVp, 200-speed system, 36-in. SID

The answer is C.
ii. EXPLANATION: Look over the choices again, keeping in mind the factors that affect recorded detail. Looking first at SID, the options may be reduced to (B) and (C) because the increase to a 40-in. SID certainly will improve recorded detail. There is one other factor that will affect detail—the speed of the system (intensifying screens). Because a slower system will render better recorded detail, the best answer is (C). The technical factors such as milliampere-seconds, kilovoltage, and grid ratio have no effect on recorded detail.

99. The Centers for Disease Control and Prevention (CDC) suggests that health care workers protect themselves and their patients from blood and body fluid contamination by using
a. strict isolation precautions.
b. standard precautions.
c. respiratory precautions.
d. sterilization.

The answer is B.
ii. EXPLANATION: Standard blood and body fluid precautions serve to protect health care workers and patients from the spread of diseases such as AIDS and AIDS-related complex. Although the precautions are indicated for all patients, special care must be emphasized when working with patients whose infectious status is unknown (e.g., the emergency trauma patient). Gloves must be worn if the radiographer may come in contact with blood or body fluids. A gown should be worn if the clothing may become contaminated. Blood spills should be cleaned with a solution of 1 part bleach to 10 parts water. (Torres et al., 6th ed., pp. 62-65)

100. How much protection is provided from a 75-kVp x-ray beam when using a 0.50-mm lead equivalent apron?
a. 51%
b. 66%
c. 88%
d. 99%

The answer is C.
ii. EXPLANATION: 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 are the most common. The 1.0-mm lead equivalent apron will provide close to 100% protection at most kVp 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. (Thompson et al, p 457)

101. Late or long-term effects of radiation exposure are generally represented by which of the following dose-response curves?
a. Linear threshold
b. Linear nonthreshold
c. Nonlinear threshold
d. Nonlinear nonthreshold

The answer is B.
ii. EXPLANATION: 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, 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.

102. The use of which of the following is (are) essential in magnification radiography?
1. High-ratio grid
2. Fractional focal spot
3. Direct exposure technique
A. 1 only
B. 2 only
C. 1 and 3 only
D. 1, 2, and 3

The answer is B.
2. EXPLANATION: Magnification radiography is used to enlarge details to a more perceptible degree. Hairline fractures and minute blood vessels are candidates for magnification radiography. The problem of magnification unsharpness is overcome by using a fractional focal spot; larger focal-spot sizes will produce excessive blurring unsharpness. Grids are usually unnecessary in magnification radiography because of the air-gap effect produced by the OID. Direct-exposure technique probably would not be used because of the excessive exposure required. (Selman, 9th ed., pp. 226-228)

103. All the following statements regarding CR IPs are true except
a. IPs do not contain radiographic film.
b. IPs use no intensifying screens.
c. IPs must exclude all white light.
d. IPs function to protect the PSP

The answer is C.
ii. EXPLANATION: 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. (Shephard, p. 51)

104. During a double-contrast BE, which of the following positions would afford the best double-contrast visualization of the lateral wall of the descending colon and the medial wall of the ascending colon?
a. AP or PA erect
b. Right lateral decubitus
c. Left lateral decubitus
d. Ventral decubitus

The answer is B.
ii. EXPLANATION: A right lateral decubitus position will demonstrate a double-contrast visualization of left-sided bowel structures, that is, the lateral side of the descending colon and the medial side of the ascending colon. A left lateral decubitus position will demonstrate a double-contrast visualization of right-sided bowel structures, that is, the lateral side of the ascending colon and the medial side of the descending colon. With the patient in the erect position, barium moves inferiorly and air rises to provide double-contrast visualization of the hepatic and splenic flexures. (Frank, Long, and Smith, 11th ed., vol. 2, p. 190)

105. 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?
1. Skeletal anomaly
2. Organ anomaly
3. Neurologic anomaly
A. 1 only
B. 2 only
C. 2 and 3 only
D. 1, 2, and 3

The answer is B.
2. EXPLANATION: 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. (Bushong, 8th ed., pp. 544-546)

106. What is the annual dose-equivalent limit for the skin and hands of an occupationally exposed individual?
a. 5 rem
b. 25 rem
c. 50 rem
d. 100 rem

The answer is C.
ii. EXPLANATION: The dose-equivalent limit for the hands and skin of an occupationally exposed individual is 50 rem (500 mSv). The dose-equivalent limit for the lens of the eye is 15 rem (150 mSv). An occupationally exposed individual may receive up to 3 rem (30 mSv) in a given calendar quarter, or 13-week period. However, that individual may not exceed 5 rem (50 mSv) in that particular year. If, for example, one received 3 rem (30 mSv) during the first 3 months of a year, that individual must not receive more than 2 rem (20 mSv) in the remaining 9 months. (Bushong, 9th ed, p 619)

108. Which of the following can affect the amount of developer replenisher delivered per film in an automatic processor?
a. Developer temperature
b. Amount of film exposure
c. Film size
d. Processor capacity

The answer is C.
ii. EXPLANATION: The film processor is automated, and replenishment quantities are preset. A microswitch is activated as a film enters the processor at the entrance rollers. Replenisher is added according to the length of the x-ray film—for as long as the detector senses the presence of film. Once the back end of the film passes the entrance roller sensor, replenishment stops. When films are fed into the processor the "long way," too much replenishment occurs, and the image can exhibit excessive density. (Shephard, p. 146)

109. The control dosimeter that comes from the monitoring company should be
a. stored in a radiation-free area
b. kept in a designated control booth
c. kept in the film-processing area
d. used as an extra badge for new personnel

The answer is A.
ii. EXPLANATION: The control badge that comes with the month's supply of dosimeters is used as a standard for comparison with the used personal badges. The control badge should be stored in a radiation-free area, away from the radiographic rooms. When it has been processed, its density is compared with the densities of the monitors worn in radiation areas. Densities greater than the density of the radiation-free monitor are reported in millirem units. (Bushong, 8th ed., p. 596)

110. A film emulsion having wide latitude is likely to exhibit
a. high density
b. low density
c. high contrast
d. low contrast

The answer is D.
ii. EXPLANATION: Every film emulsion has a characteristic curve representative of that film's speed, contrast, and latitude. A gentle curve (as opposed to a steep curve) usually indicates a film with slow speed, low contrast, and more latitude. (Shephard, p. 105)

111. Somatic effects of radiation refer to effects that are manifested
a. in the descendants of the exposed individual
b. during the life of the exposed individual
c. in the exposed individual and his or her descendants
d. in the reproductive cells of the exposed individual

The answer is B.
ii. EXPLANATION: 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. (Selman, 9th ed., p. 382)

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