Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Radiation Physics And Safety > Final Exam > Flashcards

Final Exam Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards AP® Physics flashcards
1
Q

What are the two ways of measuring radiation?

A

Old school units and SI Units

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

What are old school units (4)?

A

Roentgen (R)
Rad
REM
Curie

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

What are SI units (4)?

A

Coulombs per kilogram (C/kg)
Gray (Gy)
Sievert (Sv)
Becquerel

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

Roentgen (R) is equal to

A

Coulombs per kilogram (C/kg)

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

What is the conversion rates of old school (e.g. rad) to SI unites (e.g. Gy)?

A

1 old school = 0.01 SI unit
100 old school = 1 SI unit

E.g. 1 rad = 0.01 Gy; 1 REM = 0.01 Sv; 1 curie = 0.01 becquerel

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

Quality factor (QF) is derived from what measurement?

A

Relative Biological Effectiveness (RBE)

  • it varies with different types of radiation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the quality factor for X-ray photons

A

1

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

What is the quality factor for gamma photons

A

1

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

What is the quality factor for beta particles

A

5

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

What is the quality factor for thermal neutrons

A

5

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

What is the quality factor for fast neutrons

A

20

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

What is the quality factor for alpha particles

A

20

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

What are the Laws of Bergonie and Tribondeau (4)?

A

Cell sensitivity depends on:

  • Age (young more sensitive)
  • Differentiation (simple cells more sensitive)
  • Mitotic rate (rapidly dividing cells more sensitive)
  • Metabolic rate ( cells that use lots of energy are more sensitive)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Define “absorbed dose”

A

Energy absorbed per unit mass at a given point

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

Define “organ dose”

A

The probability of stochastic effects (mainly cancer creation) as the absorbed dose averaged over an organ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Define “equivalent dose”

A

The organ dose corrected by a radio action weighting factor that takes account of the relative biological effectiveness of the incident radiation in producing stochastic effects

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

Define “effective dose”

A

A weighted sum of equivalent doses to all relevant tissues and organ with the purpose “to indicate the combination of different doses to several different tissues in a way thatislikelyto correlate well with the total of the stochastic effects”

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

What does kerma stand for?

A

Kinetic energy released per unit mass

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

Define “Kerma”

A

Sum of kinetic energy of all charged particles liberated per unit mass

1 Kerma is ~ rad at low energies
SI unit of Kerma = Gy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What kind of effects can be either somatic or genetic?

A

Stochastic

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

What is the 10-day rule?

A

Direct pelvic radiation to fertile females should be done only during the first 10 days of menstrual cycle EXCEPT in emergencies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is stochastic?

A

Probabilistic, random.

The probability of experiencing the effect is proportional to the exposure volume, but the severity of the effect is not really affected.

“randomly determined; having a random probability distribution or pattern that may be analyzed statistically but may not be predicted precisely.”

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

What might be the results of a “severe stochastic effect” of exposure to radiography (3)?

A

Cancer
Leukemia
Mutagenesis (genetic effects)

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

Stochastic effects can be either _____ or ______ while nonstochastic effects are limited to ____

A

Stochastic: Somatic or Genetic

NONstochastic: somatic and seen in larger exposure quantities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Low dose exposure effects fall into what category?

A

Stochastic

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

What does nonstochastic mean?

A

Deterministic, predictable

The severity of the effect is proportional to the exposure volume. There is a threshold beneath which effects generally aren’t seen

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

What falls under the category of nonstochastic short-term effects (3)?

A

GI syndrome
Hematopoietic syndrome
CNS syndrome

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

What falls under the category of nonstochastic long term effects (5)?

A 
Cataract formation
Fibrosis
Organ atrophy
Loss of parenchymal cells
Reduced fertility, sterility
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Radiation exposure in the first 14 days of pregnancy increase risk of:

A

Spontaneous abortion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Radiation exposure in days 15-50 of pregnancy increase risk of

A

Organ/organ system mutations = birth defects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Radiation exposure in days 50-280 increase risk of

A

Growth retardation and development of cancers early in life

33
Q

Describe threshold vs non-threshold exposure/effect models

A

Threshold — below x-threshold NO negative effect occurs

Non-threshold — there is not threshold. Any exposure = train wreck.

34
Q

Explain linear versus non-linear exposure model once effects begin to occur

A

Linear — risk rate increases in linear way

Non-linear — risk rate changes depending on how much dose is delivered

35
Q

What is the hypothesis about radiation hormesis?

A

Radiation can be good for you in small doses

36
Q

Hormesis model is a variant of what model?

A

Threshold model

37
Q

Man-made radiation exposure rose to ______ of annual radiation dose per capita in 2006. What advanced imaging technique accounts for most of this increase?

A

1/2; CT scanning

The rise is mostly due to diagnostic imaging dose per capita which worse about 6 times the amount from 1980s

38
Q

What is ALARA principle?

A

As Low As Reasonably Achievable

39
Q

What is a personnel dosimeter?

A

A device for monitory individual occupationally exposed workers

40
Q

What is the more commonly used dosimeter by occupationally exposed individuals?

A

OSLs (optically stimulated luminescence)

41
Q

Exposing a fetus to _______ mGy (____ rad) adds about _____ cases per 1,000 deliveries to the risk of spontaneous abortion, major malformation, mental retardation, and childhood malignancy.

A

50 mGy / 5 rad

0.17 cases OR 1 case per 6K deliveries

42
Q

Below _________ exposure to fetus, there is little chance above baseline that miscarriage can be
attributed to radiation exposure

Full disclaimer: this sentence confuses me

A

100 mGy (10 rads)

43
Q

What is the chance an exposed fetus will NOT develop childhood cancer or leukemia with a fetal radiation dose of 0.05 Gy (5 rads)?

A

99%

44
Q

Low dose is now considered to be an exposure to ionizing radiation of:

A

0-20 rem

3-5 are normal in chiropractic x-ray studies which is well within the low dose levels of exposure
Helical CTs are capable of reaching dose levels outside of this

45
Q

T/F pregnancy CANNOT occur during any part of a cycle

A

FALSE.

46
Q

Pregnancy tests are better indicators than patients. Pregnancy tests require ________ before they can be administered.

A

Informed consent

47
Q

The maximum allowed exposure per year for a non-pregnant radiation worker is

A

50 mGy (5 rem)

48
Q

The maximum allowed exposure per year for a pregnant radiation worker is:

The maximum allowed exposure per year for a people under 18 yo who is occupationally exposed is:

HINT: its the same for these groups of people

A

5 mGy (0.5 rem)

49
Q

Who owns radiographs?

A

The facility/practitioner who took them

50
Q

People who are occupationally exposed to radiation may need to be monitored. Why?

A

If the state thinks it is possible that they receive at or above 25% of annual maximum permissible dose

E.g. if you are pregnant or under 18 yo your max is 5 mGy. If they think you are getting more than 1.25 mGy they can monitor you.

51
Q

What does a positive correction factor mean?

A

Th machine is under-producing x-rays compared to the average or benchmark machine

52
Q

What does negative correction factor mean?

A

The machine is over-producing as compared to average or benchmark machine

53
Q

Once the TCF and part measurement are in the calculator… you can

(Um, what is TCF?)

A

choose any kVp and the calculator will show you the correct mAs for that kVp

54
Q

What 3 things could you do that would require you to re-calculate the machine correction factor?

A
  • install new X-ray tube
  • install new auto processor
  • replace radiographic screens in x-ray cassettes
55
Q

Image critique: every film should have

A

3 visible margins of collimation

56
Q

Image critique: a mildly over-penetrated (too dark) image will require ____ (a percent) _____ [reduction/increase} in mAs to correct for density

A

30% reduction in mAs

Restating the same thing:
Too dark/over penetrated = reduce mAs 30%

57
Q

Q stem1/3. If contrast is too high, the bones will be white but the soft tissues will be nearly invisible. What is the problem?

A

Contrast

58
Q

Q stem 2/3. If contrast is too high, the bones will be white but the soft tissues will be nearly invisible. If this were a low density problem (ok, so now you know it’s not) what would the image look like (bones and soft tissue)

A

White bones accompanied by very prominent soft tissue visibility

59
Q

Q stem 3/3. If contrast is too high, the bones will be white but the soft tissues will be nearly invisible. How would you correct this problem of too high contrast and what will it do?

A

Increase kVp 15%, half the mAs

It creates higher energy beam

60
Q

Image critique: Conditions that cause fluid accumulation in the lungs will require more

A

mAs to penetrate normal technique

61
Q

Image critique: Conditions that cause fluid accumulation in the lungs will require how much more mAs?

A

50%

62
Q

How many vertebra do you need to get in a lateral cervical spine film?

A

the entire C7 vertebral body must be visible.

63
Q

Having a random probability distribution or pattern that may be analyzed statistically but may not be predicted precisely. The probability of experiencing the effect of radiation is proportional to the exposure volume, but the severity of the effect is not affected.

A

Stochastic effects

64
Q

What are the characteristics of stochastic effects of radiation?

A 
Random
Unpredictable
Low dose effects
Latent period from years to decades
May be somatic or genetic
May cross generations
Operate on non-threshold model of risk estimation
65
Q

What are examples of stochastic effects of radiation?

A

Stochastic effects can be either somatic or genetic

Ex: cancer, leukemia, genetic effects/mutagenesis

66
Q

When are stochastic effects seen with radiation?

A

After low dose exposure

67
Q

Radiation effect in which the severity of the effect is proportional to the exposure volume. There is a threshold beneath which effects
generally aren’t seen

A

Nonstochastic

68
Q

When are non-stochastic effects of radiation seen?

A

After large dose exposure in short period of time

69
Q

What are examples of non-stochastic effects of radiation?

A

Effects are limited to somatic:

Short-term effects…
- GI Syndrome 
- Hematopoietic syndrome 
- CNS syndrome
Later effects can also occur:
- Cataract formation 
- Fibrosis 
- Organ atrophy 
- Loss of parenchymal cells 
- Reduced fertility, sterility
70
Q

What are characteristics of non-stochastic radiation effects?

A

Deterministic
Predictable
Seen with higher dose exposure
Operate on threshold model of risk estimation

71
Q

What are the 4 viable models of risk estimation (relation between exposure and effect)?

A

Linear non-threshold
Non-linear non-threshold
Linear threshold
Non-linear threshold

72
Q

What is the prevailing model for risk estimation?

A

Linear non-threshold model

73
Q

What is the difference between a linear vs. non-linear exposure models of risk estimation?

A

Linear suggests the rate of risk is proportional and linear to dose
Non-linear suggests that the rate of risk changes depending on dose delivered

74
Q

What is the difference between threshold and non-threshold exposure/effect models?

A

Threshold suggests that there is a dose below which there is no negative effect
Non-threshold suggests that there is no safe dose - all exposure is deleterious

75
Q

What is radiation Hormesis

A

The hypothesis that radiation can be good for you at small doses (1-50 mSv). The hormesis model of risk estimation is a variant of non-linear threshold model for radiation exposure

76
Q

What has accounted for most of the increase in per capita radiation exposure since the 1980’s?

A

CT scanning

Radiation Physics And Safety (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions