Extra Review Flashcards

1
Q

Which populations were used as sources of data on the incidence of radiation-induced cancer?

A
  • Atomic bomb survivors
  • Medically exposed patients
  • Occupational exposed personnel
  • Populations who received high natural background exposure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the limitations on epidemiologic studies?

A
  • Failure to control experimental groups
  • Insufficient observation periods
  • Using improper control groups
  • Deficient or Incorrect health records
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Which of the following describes radiation damage that increases the probability of causing a late effect but will not increase the severity of the effect?

A

Stochastic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What’s the dose response relationship for Radiation-induced leukemia

A

linear-nonthreshold dose relationship

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What’s the dose response relationship for Skin cancer

A

threshold

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What’s the dose response relationship for Thyroid cancer

A

linear nonthreshold

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What’s the dose response relationship for Osteosarcoma

A

linear-quadratic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What’s the dose response relationship for lung cancer

A

linear-nonthreshold

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The function of a filter is to remove what from the x-ray beam?

A

Long wavelength radiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

To within what percent of the SID must the collimator light and actual irradiated area be accurate?

A

2%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

The greatest beam limitation is accomplished when the cone/cylinder is _____, and the diameter opening is _____.

A

longer ; smaller

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How much total filtration is required when using over 70 kVp?

A

2.5 mm of aluminum equivalent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The number of repeat radiographs can be reduced by

A

eliminating voluntary patient motion using immobilization devices

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Using CR, it is estimated that overexposures of up to _____, and underexposures up to _____ are recoverable, thus eliminating the need for retakes.

A

500% ; 80%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

An effective way of reducing patient dose is through

A

Accurate and effective positioning

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Causes of repeat radiographs include the following:

A
  • Dirty screens
  • Incorrectly loaded cassettes
  • Light leaks
  • Chemical fog
  • Processor artifacts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How tall must primary protective barriers be?

A

7 ft.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Leakage radiation from the x-ray tube housing shall not exceed _____ mR/hr at a distance of 1 meter from the tube.

A

100

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Lead aprons worn during a mobile exam must have a lead equivalency of at least _____ mm.

A

0.5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

The cardinal rules of radiation protection include:

A
  • Time
  • Distance
  • Shielding
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

When wearing a lead apron, a pregnant radiographer is required to wear their fetal dosimeter

A

at the waist level on the inside of the apron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Factors which determine protective barrier thickness include:

A
  • Time of occupancy
  • Workload
  • Use
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Applying the inverse square law, if we double our distance from the source, the intensity at our new distance is _____ as much as the original intensity

A

1/4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

The lethal dose required to kill 50% of the population in 30 days is the definition of

A

LD 50/30

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

The acute radiation syndrome includes the following:

A
  1. Bone marrow syndrome
  2. Gastrointestinal (GI)
  3. Central nervous system (CNS) syndrome
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

For the acute radiation syndrome, in the 100-1,000 R range, death is mostly the result of damage to the _____ system

A

hemopoietic (development of blood cells)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

In the _____ stage, the person experiences nausea, vomiting, and diarrhea.

A

prodromal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

In the _____ stage, the person appears to be symptom-free

A

latent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

In the _____ stage, the person becomes noticeably ill and shows signs and symptoms of the specific syndrome reflecting the organ system which is damaged.

A

manifest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

define chromatid aberration

A
  • Occurs after DNA synthesis
  • During the S-phase, a chromosome duplicates itself, creating sister chromatids
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

define chromosomal aberration

A
  • Occurs before DNA synthesis
  • Both daughter cells inherit a damaged chromatid
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

what are the 2 types of damage in chromosomal aberration?

A
  • single break damage
  • double break damage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

define single-break damage

A
  • Chromosome arm is broken off
  • Deletion - arm does not reattach itself
  • Inversion - inverts and reattaches itself
  • Duplication - attaches itself to a different chromosome
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

define double-break damage

A
  • Two portions of a chromosome are broken off
  • interstitial deletion - both broken pieces do not reattach
  • Inversion - if both pieces reattach themselves
  • Duplication - if one or both arms attach to a different chromosome
  • Translocation - two chromosomes exchange pieces
35
Q

define Radiation cataractogenesis

A

formation of cataracts formed by radiation

36
Q

define Alopecia

A

hair loss

37
Q

define Erythema

A

redness of the skin

38
Q

define Desquamation

A

peeling of the skin

39
Q

define Inflammation

A

swelling and reddening of the skin

40
Q

define Atrophy

A

shrinking of the tissue or organ

41
Q

Personnel monitoring devices include all of the following except the ____ dosimeter.

A

scintillation

42
Q

Which instrument detects the presence of radiation rather than measuring it?

A

Geiger muller

43
Q

Diagnostic radiology personnel may receive an annual dose limit of:

A

5rem (50 mSv)

44
Q

Dose limits are based on a ________________ dose-response relationship to radiation.

A

linear ; nonthreshold

45
Q

The dose limit for the general public is _______ the dose limit for occupational exposure.

A

1/10

46
Q

What factors can decrease the dose to the limited operator?

A
  • time
  • distance
  • shielding
47
Q

The unit of the SI system used to measure the equivalent dose is the:

A

sievert

48
Q

The SI unit for measuring absorbed dose is the:

A

Gray

49
Q

The unit commonly used to report the effective dose to occupational workers in the United States is:

A

mSv

50
Q

What does ALARA stand for? Why is this concept the guiding principal to the field of radiology?

A
  • As low as reasonably achievable
  • this concept emphasizes the protection against radiation. To minimize the ionizing radiation exposure as much as possible to avoid occupational or patient dose.
51
Q

What are the units of measurement for Exposure, Absorbed Dose and Equivalent/ Effective Dose? List both the conventional and SI units for each.

A
  • Exposure =Roentgen (R) / 2.58 x 10-4 C/kg
  • Absorbed Dose = Rad (rad) / 0.01 Gy
  • Equivalent/ Effective Dose = Rem (rem) / 0.01 Sv
52
Q

What are the types of dosimeters? Which is the most common and why?

A

Personnel Dosimeters:
- Film Badges
- TLD (Thermoluminescent dosimeter)
- OSR (optically stimulated luminescence)
- pocket dosimeters
> most common would-be film badges
> they’re inexpensive
> simple to use

53
Q

Where should dosimeter badges be worn? Where should fetal dosimeter badges be worn?

A
  • dosimeters should be worn at the collar level
  • fetal dosimeters must be worn at the abdominal area
54
Q

What is declaration of pregnancy? How is it executed?

A
  • declaration of pregnancy is when the worker voluntarily reveals her pregnancy to the employer.
  • The RSO (radiation safety officer) will then council with her to follow proper radiation protection
  • can be limited to exams
  • cannot be expelled from work
  • minimizing the radiation exposure as much as possible
55
Q

What is the effective annual dose limit for radiology personnel?

A
  • The cumulative whole-body effective dose limit is calculated by multiplying one’s age in years by 1 rem (10 mSv).
  • 5 rem (50 mSv)
56
Q

Which dose-response relationship are dose limits and radiation protection based upon?

A

dose limits are based on linear nonthreshold relationships

57
Q

Which governing body is responsible for establishing dose limits and protection guidelines?

A

nuclear regulatory commission (NRC)

58
Q

What is a dosimetry report? Who is responsible for monitoring it?

A
  • dosimetry report is film badges, TLD, OSL, and pocket dosimeters being collected every month
  • The RSO (radiation safety officer) monitors the reports to retrieve and distribute to employees
59
Q

What is the difference between a personnel monitor and a field-survey instrument?

A
  • personnel monitors measure the radiation a worker is being exposed to
  • field survey are devices used to detect and measure the radiation in an area
60
Q

What is the dose limits for Whole-Body? Include both convention and SI units

A

5 rem (50mSv)

61
Q

What is the dose limits for Lens of Eye? Include both convention and SI units

A

15 rem (150mSv)

62
Q

What is the dose limits for Skin/ Extremities? Include both convention and SI units

A

50 rem (500 mSv)

63
Q

What is the dose limits for Whole-body cumulative? Include both convention and SI units

A

Age x 1rem (Age x 10 mSv)

64
Q

What is the dose limits for Fetus? Include both convention and SI units

A
  • 10 months/280 days = 0.5 rem(5 mSv)
  • 1 month/28 days = 0.05 rem (0.5 mSv)
65
Q

What is the dose limits for Public Exposure? Include both convention and SI units

A
  • Infrequent exposure = 0.5 rem (5 mSv)
  • Frequent exposure = 0.1 rem (1 mSv)
66
Q

What are the guiding principals of reducing the possibility of radiation exposure?

A

Cardinal principles
- time
- distance
- shielding

67
Q

As LET ____________, the RBE ______________.

A

increases ; increases

68
Q

Tissue is _______ radiosensitive under high oxygen conditions and _________ radiosensitive under hypoxic conditions.

A

more ; less

69
Q

A _________ response to radiation is directly proportional to the dose received.

A

linear

70
Q

If a response to radiation is expected, no matter how small the dose, then that dose-response is _________________.

A

nonthreshold

71
Q

Radiation induced genetic damage follows a ___________________ dose-response relationship.

A

linear ; nonthreshold

72
Q

define LET

A
  • linear energy transfer
  • rate of charged particles going through matter
73
Q

define OER

A
  • oxygen enhancement ratio
  • OER = dose in rads bio. response in anoxic conditions / dose in rads bio. response in aerobic conditions
74
Q

What are the two components of beam restriction? How are each of them important?

A
  • kilovoltage
  • irradiated material
75
Q

What are the common beam-limiting devices?

A
  • diaphragms
  • cones
  • collimator
76
Q

What is the purpose of x-ray beam filtration?

A
  • The purpose of x-ray beam filtration is to absorbed low energy photons from exiting the tube to reduce patient dose
  • remove long wavelength radiation
77
Q

Explain inherent filtration, added filtration and total filtration?

A

inherent - consists of the glass window of the X-ray tube and the cooling oil surrounding the tube housing

added - consists of aluminum or aluminum equivalent (Al eq.) of appropriate thick- ness inserted outside the glass window of the tube housing.

total - combination of inherent + added

78
Q

What is the minimum Al/Eq for filtration above 70 kVp?

A

2.5 mm of Al EQ

79
Q

What are the 3 types of gonad shields? When should they be employed?

A
  • flat contact shield
  • shadow shield
  • shape contact shield
80
Q

Describe how exposure techniques can be used to influence patient dose.

A
  • With kVp, it is desired to have a low setting, as it deals with quantity. kVp also has a direct relationship with exposure.
  • The higher the kVp, the higher the patient dose
  • mAs deals with quality, having a direct relationship with density and exposure
  • The minimum patient dose is a high kVp with a low mAs
  • As long as the settings balance themselves out to maintain a radiographic balance, having a high kVp or vice versa is acceptable (technique settings also depends on the part being examined)
81
Q

Why is patient positioning important in reducing patient dose?

A
  • With the correct positioning, it will allow the radiographer to produce a high quality image.
  • With all the correct angles, it can be observed once dealt with by the doctor.
  • With correct positioning, there are no mistakes, thus reducing retakes and reducing patient dose
82
Q

Why is it important for a technologist to always ask their female patients of child-bearing age whether they are pregnant?

A
  • It is important to make sure the patient is not pregnant to avoid high exposure radiations during exams
  • When pregnant, safety procedures need to be made to keep the fetus safe from radiation.
83
Q

Give examples of some causes of repeat radiographs and how to avoid them.

A
  • Incorrect positioning
  • Processor artifacts
  • Dirty screens
  • Chemical fog
  • Grid errors