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1. A student radiographer who is under 18 years of age must not receive an annual occupational dose of greater than

0.1 rem (1 mSv)

0.5 rem (5 mSv)

5 rem (50 mSv)

10 rem (100 mSv)
•
• 0.1 rem (1 mSv)
2. 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

1 and 2 only

2 only

1 and 3 only

1, 2, and 3
•
•
• 1, 2, and 3
3. The exposure rate to a body 4 ft from a source of radiation is 16 R/h. What distance from the source would be necessary to decrease the exposure to 6 R/h?

5 ft

7 ft

10 ft

14 ft
•
•
• 7 ft
•  The relationship between x-ray intensity and distance from the source is expressed by the inverse-square law of radiation. The formula is
• Substituting known values:

• Thus, x = 6.5 ft (necessary to decrease the exposure to 6 R/h). Note that in order for the exposure rate to decrease, the distance from the source of radiation must increase. (Bushong8th ed.p. 68)
4. Occupational radiation monitoring is required when it is likely that an individual will receive more than what fraction of the annual dose limit?

½

¼

1/10

1/40
•
•
• 1/10
• Different types of monitoring devices are available for the occupationally exposed, and anyone who might receive more than one-tenth the annual dose limit must be monitored. Ionization is the fundamental principle of operation of both the film badge and the pocket dosimeter. In the film badge, the film's silver halide emulsion is ionized by x-ray photons. The pocket dosimeter contains an ionization chamber (containing air), and the number of ions formed (of either sign) is equated to exposure dose. TLDs are radiation monitors that use lithium fluoride crystals. Once exposed to ionizing radiation and then heated, these crystals give off light proportional to the amount of radiation received. OSL dosimeters are radiation monitors that use aluminum oxide crystals. These crystals, once exposed to ionizing radiation and then subjected to a laser, give off luminescence proportional to the amount of radiation received. (Bushong8th ed.p. 593)
5. The radiographer's radiation monitor report must include which of the following information?
2. Quarterly dose equivalent
3. Inception date

1 only

1 and 2 only

2 and 3 only

1, 2, and 3
•
•
• 1, 2, and 3
6. Some patients, such as infants and children, are unable to maintain the necessary radiographic position without assistance. If mechanical restraining devices cannot be used, which of the following should be requested or permitted to hold the patient?

Transporter

Patient's father

Patient's mother

•
•
• Patient's father
7. The likelihood of adverse radiation effects to any radiographer whose dose is kept below the recommended guideline is

very probable

possible

very remote

zero
•
•
• very remote
8. f an exposure dose of 50 mR/h is delivered from a distance of 3 ft, what would be the dose delivered after 20 minutes at a distance of 5 ft from the source?

6 mR

18 mR

46 mR

138 mR
•
•
• 6 mR
• <correct.opt style="color: rgb(78, 78, 78); font-family: 'Open Sans'; font-size: 15px; line-height: 22.5px;">A The relationship between x-ray intensity and distance from the source is expressed by the inverse-square law of radiation. The formula is
• Substituting known values:

• Thus, x = 18 mR/h (60 minutes) and, therefore, 6 mR in 20 minutes. Distance has a profound effect on dose received and, therefore, is one of the cardinal rules of radiation protection. As distance from the source increasesdose received decreases. (Bushong8th ed.pp. 68–70)
9. Which of the following contributes most to occupational exposure?

The photoelectric effect

Compton scatter

Classic scatter

Thompson scatter
•
•
• Compton scatter
10. If the ESE for a particular exposure is 25 mrad, what will be the intensity of the scattered beam perpendicular to and 1 m from the patient?

•
•
• The patient is the most important radiation scatterer during both radiography and fluoroscopy. In general, at 1 m from the patient, the intensity is reduced by a factor of 1,000 to about 0.1% of the original intensity. Successive scatterings can reduce the intensity to unimportant levels. Calculate that 0.1% of 25 mrad is 0.025 mrad. (Bushong8th ed.p. 572)
11. Sources of secondary radiation include

1 only

1 and 2 only

2 and 3 only

1, 2, and 3
•
•
• 2 and 3 only
12. If an individual receives 50 mR while standing 4 ft from a source of radiation for 2 minutes, which of the following option(s) will most effectively reduce his or her radiation exposure to that source of radiation?

Standing 3 ft from the source for 2 minutes

Standing 8 ft from the source for 2 minutes

Standing 5 ft from the source for 1 minute

Standing 6 ft from the source for 2 minutes
•
•
• Standing 8 ft from the source for 2 minutes
13. According to the NCRP, the total gestational dose equivalent limit for the pregnant radiographer is

1 mSv

5 mSv

15 mSv

50 mSv
•
•
• 5 mSv
14. According to NCRP regulations, leakage radiation from the x-ray tube must not exceed

10 mR/h

100 mR/h

10 mR/min

100 mR/min
•
•
• 100 mR/h
15. Personnel present in the x-ray room during fluoroscopic examinations wear lead aprons to protect them primarily from

photoelectric scatter.

Compton scatter.

pair production.

magnetic fringe field.
•
• Compton scatter.
16. To be in compliance with radiation safety standards, the fluoroscopy exposure switch must

sound during fluoro-on time

be on a 6-ft-long cord

terminate fluoro after 5 minutes

•
•
• be the “dead man” type
17. How much protection is provided from a 100-kVp x-ray beam when using a 0.50-mm lead-equivalent apron?

40%

75%

88%

99%
•
•
• 75% 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)
18. The amount of time that x-rays are being produced and directed toward a particular wall is referred to as the

use factor

occupancy factor

controlling factor
•
• use factor
19. Radiation dose to personnel is reduced by which of the following exposure control cord guidelines?

1. Exposure cords on fixed equipment must be very short.

2. Exposure cords on mobile equipment should be fairly long.

3. Exposure cords on fixed and mobile equipment should be of the coiled, expandable type.

1 only

1 and 2 only

2 and 3 only

1, 2, and 3
•
•
• 1 and 2 only
20. Each time an x-ray beam scatters, its intensity at 1 m from the scattering object is what fraction of its original intensity?

1/10

1/100

1/500

1/1,000
•
•
• 1/1,000
• One of the radiation protection guidelines for the occupationally exposed is that the x-ray beam should scatter twice before reaching the operator. Each time the x-ray beam scatters, its intensity at 1 m from the scattering object is one-thousandth of its original intensity. Of course, the operator should be behind a shielded booth while making the exposure, but multiple scatterings further reduce the danger of exposure from scattered radiation. (Bushong8th ed.p. 572)
21. What percentage of x-ray attenuation does a 0.5-mm lead equivalent apron at 100 kVp provide?

51%

66%

75%

94%
•
•
• 75%
• Lead aprons are worn by occupationally exposed individuals during fluoroscopic and mobile x-ray procedures. Lead aprons are available with various lead equivalents; 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 lead equivalent apron will attenuate about 99.9% of a 50-kVp beam, 88% of a 75-kVp beam, and 75% of a 100-kVp beam. (Bushong, p 597)
22. Which of the following features of fluoroscopic equipment is (are) designed especially to minimize radiation exposure to the patient and/or personnel?

1. Bucky slot cover

2. Exposure switch/foot pedal

3. Cumulative exposure timer

1 only

1 and 2 only

2 and 3 only

1, 2, and 3
•
•
• 1, 2, and 3
23. The single most important scattering object in both radiography and fluoroscopy is the

x-ray table

x-ray tube

patient

IR
•
•
• patient
24. Radiation that passes through the tube housing in directions other than that of the useful beam is termed

•
•
25. ____ and ______ radiations are those that have deviated in direction while passing through a part.
• Scattered
• secondary
26. Which of the following statements regarding the pregnant radiographer is (are) true?

1. She should declare her pregnancy to her supervisor.

2. She should be assigned a second personnel monitor.

3. Her radiation history should be reviewed.

1 only

1 and 2 only

2 and 3 only

1, 2, and 3
•
• 1, 2, and 3
27. The dose equivalent limit for a radiography student under the age of 18 years is

7 rem.

5 rem.

0.5 rem.

0.1 rem.
•
•
• 0.1 rem.
28. Whole-body annual occupational DL (dose limit) is __ rem (5,000 millirem; ___ mSv).
• 5
• 50
29. radiography students under the age of 18. Their annual whole-body annual occupational DL must not exceed ___ rem (100 mrem; __ mSv).
• 0.1
• 1mSy

30. The usual annual DL for the general public is ___ rem (___ mrem; _ mSv).
•  0.5 rem
• 500mrem
• 5mSv
31. How much protection is provided from a 75-kVp x-ray beam when using a 0.50-mm lead equivalent apron?
•
• 88%
32. A 0.25-mm lead equivalent apron will attenuate about__% of a 50-kVp x-ray beam,
97%
33. A 0.25-mm lead equivalent apron will attenuate about a  __% of a 75-kVp beam,
66%
34. A 0.25-mm lead equivalent apron will attenuate about  __% of a 75-kVp be
66%
35. Secondary radiation barriers usually require the following thickness of shielding:

•
36. All the following statements regarding mobile radiographic equipment are true except

the exposure cord must permit the operator to stand at least 6 ft from the patient, x-ray tube, and useful beam

exposure switches must be the two-stage type

a lead apron should be carried with the unit and worn by the radiographer during exposure

the radiographer must alert individuals in the area before making the exposure
•
• exposure switches must be the two-stage type
37. How is the intensity of an x-ray photon affected after each time it scatters?

Its intensity increases 4 times.

Its intensity increases 1000 times.

Its intensity decreases 4 times.

Its intensity decreases 1000 times.
•
•
• Its intensity decreases 1000 times.
38. What is the intensity of scattered radiation perpendicular to and 1 m from a patient compared with the useful beam at the patient's surface?

0.01%

0.1%

1.0%

10.0%
•
•
• 0.1%
39. If an individual receives an exposure of 150 mR/h at a distance of 2 feet from a radiation source, what will be their dose after 30 minutes at a distance of 5 feet from the source?

60 mR

30 mR

24 mR

12 mR
•
•
• 12 mR
40. The correct way(s) to check for cracks in lead aprons is (are)

1. to fluoroscope them once a year

2. to radiograph them at low kilovoltage twice a year

3. by visual inspection

1 only

1 and 2 only

2 and 3 only

1, 2, and 3
•
• 1 only

the photoelectric effect

Compton scatter

classic scatter

pair production
•
•
• Compton scatter
42. Protective devices such as lead aprons function to protect the user from

2. the primary beam

1 only

1 and 2 only

1 and 3 only

1, 2, and 3
•
•
• 1 only
43. The Bucky slot cover is in place to protect the

1. patient

2. fluoroscopist

3. technologist

1 only

1 and 2 only

2 and 3 only

1, 2, and 3
•
•
• 2 and 3 only
44. Primary radiation barriers usually require which thickness of shielding?

•
•
45. The minimum requirement for lead-equivalent content in protective aprons is

0.05 mm Pb.

0.50 mm Pb.

0.25 mm Pb.

1.0 mm Pb.
•
•
• 0.25 mm Pb.
46. Lead aprons are secondary radiation barriers and must contain at least ____ (1/4) mm Pb equivalent
0.25
 Author: McCrae ID: 295638 Card Set: Radiation_Protection_Personnel_protection[1].txt Updated: 2015-02-12 05:04:11 Tags: mosb Folders: Description: mosbly Rad Review Show Answers: