Health Physics I: Unit 3 Review Flashcards

Unit 3 Review, Chapter 10, 12, 14

1
Q

Working in conjunction with their partners in other agencies, the FDA takes action to:

A

Promote safe use of medical imaging devices
Support informed clinical decision
Increase patient awareness

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2
Q

ALARA concept adopts an extremely conservative model with respect to the relationship between:

A

Ionizing radiation and potential risk

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3
Q

The main function of the Nuclear Regulatory Commission (NRC):

A

Oversee the nuclear energy industry

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4
Q

Run by the government of Japan, primarily studies Japanese atomic bomb survivors:

A

Radiation Effects Research Foundation

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5
Q

Functions and/or responsibilities of the United States Occupational Safety and Health Administration (OSHA):

A

Monitoring agency in places of employment, predominantly in industry
Responsible for regulations concerning an employee’s “right to know” with regard to hazards in the workplace

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6
Q

Effective dose (EfD) limit for the lens of the eye:

A

15 mSv

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7
Q

Occasional exposure for the purpose of education and training is permitted, provided that the annual effective dose limit of __ is not exceeded for persons under the age of 18 years.

A

1 mSv annually

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8
Q

Responsibilities of a health care facility’s radiation safety committee (RSC):

A

Provide guidance for the radiation safety program

Facilitate the ongoing operation of the radiation safety program

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9
Q

Effective dose (EfD) limits may be specified for:

A

Whole-body exposure
Partial-body exposure
Exposure of individual organs

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10
Q

If a dose of radiation produces a skin burn, a higher dose of radiation will cause the skin burn to be more severe; however, a dose below the threshold level for skin burn will:

A

not demonstrate the effect

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11
Q

The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) evaluates human and environmental ionizing radiation exposures from a variety of sources, including:

A

Radioactive materials
Radiation-producing machines
Radiation accidents

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12
Q

Epidemiologic studies of atomic bomb survivors exposed in utero have provided evidence of a dose-dependent increase in the incidence of intellectual disability for fetal doses greater than approximately:

A

0.4 Sv

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13
Q

The essential concept underlying radiation protection:

A

any organ in the human body is vulnerable to damage from exposure to ionizing radiation

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14
Q

Random effect of ionizing radiation

A

Stochastic event

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15
Q

Agency was previously known as the Atomic Energy Commission

A

Nuclear Regulatory Commission (NRC)

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16
Q

To provide a low-exposure cut-off level for negligible risk, agencies have established an annual negligible individual dose (NID) of __ .

A

0.01 mSv/year

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17
Q

A radiation safety officer in a health care facility must have sufficient authority, organizational freedom, and management prerogative to:

A

Identify radiation safety problems
Initiate, recommend, or provide corrective action
Stop unsafe operations involving by-product material
Verify implementation of corrective actions.

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18
Q

The responsibility for maintaining radiation monitoring records for all personnel and for providing counseling for individuals who receive monitor readings in excess of allowable limits:

A

Radiation safety officer

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19
Q

Upper boundary radiation exposure limits for occupationally exposed persons are associated with risks that are similar to other industries, which include:

A

Manufacturing
Trade
Government

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20
Q

Health care facilities usually adopt investigation levels, defined as level I and level II. In the United States, these levels are traditionally __ to __ the applicable regulatory standards

A

1/10 to 3/10

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21
Q

Common reasons for unacceptable images:

A

Patient mispositioning
Incorrect centering of the radiographic beam
Patient motion during the radiographic exposure
Incorrect collimation of the radiographic beam

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22
Q

Involuntary motions that cannot be willingly controlled

A
Chills
Tremors
Muscle spasms
Pain
Active withdrawal
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23
Q

Lack of control over voluntary motion may be attributed to:

A
The patient’s age
Breathing patterns or problems
Physical discomfort
Fear of the examination
Mental instability
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24
Q

The first step in protection of the reproductive organs:

A

Precise collimation of the radiographic beam to include only the anatomy of interest

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25
Q

Areas of the body that should be shielded from the useful beam whenever possible:

A

Lens of the eye
Breasts
Thyroid gland
Reproductive organs

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26
Q

Benefits of a repeat analysis program:

A

Increased awareness among radiographers of the need to produce optimal quality recorded images
Radiographers become more careful in producing radiographic images
In-service education programs covering these specific topics may be designed for imaging personnel

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27
Q

If a pregnant patient is inadvertently irradiated:

A

Radiation safety officer (RSO) or the medical physicist should perform the calculations necessary to determine fetal dose

28
Q

Frequently a problem in diagnostic pediatric radiography:

A

Patient motion

29
Q

A type of gonadal shield that provides maximal gonadal protection for a male patient when AP, oblique, and lateral projections:

A

Shaped contact shield containing 1 mm of lead

30
Q

Examples of nonessential radiographic examinations:

A

A chest x-ray examination automatically scheduled on admission to the hospital
Lumbar spine x-ray examination as part of a pre-employment physical
Whole-body computed tomography (CT) screening

31
Q

When a properly calibrated automatic exposure control (AEC) is not employed:

A

Use standardized technique charts that have been established for each x-ray unit

32
Q

Because multiple bony areas span the entire body, the radiation dose absorbed by the organ called bone marrow:

A

Cannot be measured by a direct method; it can only be estimated

33
Q

Damage to the newborn is unlikely for doses below

A

0.2 Gy

34
Q

Reducing the field size to the anatomic features of interest:

A

Reduces patient exposure

Increases recorded image quality by decreasing scatter

35
Q

The genetically significant dose (GSD) for the population of the United States is approximately:

A

0.20 mSv

36
Q

Specific area shielding may be selectively used during some x-ray procedures to protect:

A

Reproductive organs
Lens of the eye
Breast tissue

37
Q

Effective means to limit the patient’s exposure to ionizing radiation:

A

Utilize appropriate radiation reduction techniques
Use protective devices that minimize radiation exposure
Select higher kVp and lower mAs

38
Q

Sensing devices most often used to measure skin dose directly:

A

Thermoluminescent dosimeters

39
Q

Neglecting to use standardized technique charts may result in:

A

Poor-quality image
Repeat examinations
Unnecessary exposure of the patient

40
Q

Diagnostic medical procedures result in fetal exposures of less than:

A

0.01 Gy, the risk of abnormality is very small

41
Q

Analysis of radiographic repeat rates provide what type of benefits:

A

Provides information for process improvement
Helps minimize patient exposure
Improves overall performance of the imaging department.

42
Q

What effect does a repeat image have on the radiation dose received by the patient?

A

The patient’s skin and possibly the gonads receive a double radiation dose

43
Q

Alternate term for use factor (U):

A

Beam direction factor

44
Q

The dose rate to personnel located within a meter of the patient during a c-arm procedure compares to routine fluoroscopy:

A

C-arm and routine fluoroscopy are comparable in dose rates

45
Q

Determines the shielding requirements for a particular imaging facility:

A

Medical physicist

46
Q

Because exposure from radiation-related jobs will not alter the __, radiation workers may receive a larger equivalent dose than members of the general population.

A

genetically significant dose

47
Q

X-rays scattered from the patient’s body should scatter a minimum of ____ times before reaching a controlled area.

A

2

48
Q

If the peak energy of the x-ray beam is 100 kVp, a protective lead apron must be the equivalent to at least:

A

0.25-mm thickness of lead

49
Q

The radiation output weighted time that the unit is actually delivering radiation during the week:

A

Workload

50
Q

Protective eyeglasses fitted with optically clear lenses that contain a minimal lead equivalent protection level should be _____ thick.

A

0.35 mm

51
Q

The lifetime effective dose in mSv should not exceed:

A

10 times the occupationally exposed person’s age in years

52
Q

Radiation-shielding design considerations:

A

The mean energy of the x-rays that will strike the barrier
Whether the barrier is of a primary or secondary nature
The workload of the unit
The use factor of the unit
The occupancy factor behind the barrier

53
Q

Part(s) of a diagnostic x-ray unit that should not be touched while a radiographic exposure is in progress:

A

Tube housing
Collimator
High-tension cables

54
Q

Diagnostic imaging personnel routinely receive the highest occupational exposure during the following procedures:

A

Fluoroscopy
Mobile radiography
X-ray special procedures (Interventional radiography)

55
Q

The maximum weekly permitted equivalent dose for a controlled area:

A

1 mSv

56
Q

The intensity of the x-ray beam is inversely proportional to the square of the distance from the source, how does the intensity of the x-ray beam change when the distance from the source of radiation and a measurement point is tripled?

A

Decreases by a factor of 9 at the new distance

57
Q

The intensity of the x-ray beam is inversely proportional to the square of the distance from the source.

A

Inverse square law

58
Q

Adjustments in technical exposure factors that decrease the production of scattered radiation:

A

Increase kVp and decrease mAs accordingly

59
Q

X-ray examinations when a radiographer wear a thyroid shield:

A

Fluoroscopy and x-ray special procedures

60
Q

Term that represents a portion of beam-on time that the x-ray beam is directed at a primary barrier during the week:

A

Use factor

61
Q

Appropriate steps when a radiologic technologist declares her pregnancy to her employer:

A

She continues to perform her duties without interruption of employment
She receives radiation safety counseling
She follows established radiation safety practices

62
Q

Secondary radiation includes:

A

Leakage radiation

Scatter radiation

63
Q

A protective curtain with a minimum of 0.25-mm lead equivalent, should normally be positioned between the fluoroscopist and the patient to intercept which type radiation?

A

Scatter radiation

64
Q

X-ray procedures that increase the radiographer’s risk of exposure to ionizing radiation:

A

Mobile C-arm fluoroscopy
Interventional procedures that use high level control fluoroscopy
Mobile radiographic examinations

65
Q

When scattered radiation decreases, the radiographer’s exposure:

A

Decreases

66
Q

When the time spent in a higher radiation area is reduced or limited, occupational exposure:

A

Decreases

67
Q

The annual effective dose limit for individual members of the general population not occupationally exposed is __ from artificial sources other than medical irradiation and natural background and __ for infrequent annual exposure

A

1 mSv

5 mSv