Brainscape's Knowledge GenomeTM

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


See full index

Registry Review > Radiation Protection (ch.3) > Flashcards

Radiation Protection (ch.3) Flashcards

1
Q

radiation weighting factor (Wr) is

A

a number assigned to different TYPES of radiations in order to better determine their effect on tissue, such as xrays vs alpha particles.

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

monthly gestational dose-equivalent limit for embryo/fetus of a pregnant radiographer is

mSv?

A

5 mSv
500 mrem
not to exceed .5 mSv in 1 month

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

annual occupational whole body dose equivalent limit

mSv?
rem?

A

50 mSv

5 rem

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

annual occupational whole body dose equivalent limit for students under 18

mSv?
rem?

A

1 mSv
.1 rem
100 mrem

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

annual occupational dose equivalent limit for the lens of the eye

mSv?
rem?

A

150 mSv

15 rem

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

annual occupational dose equivalent limit for the thyroid, skin, and extremities is

mSv?
rem?

A

500 mSv

50 rem

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

a time of 1.5 mins is required for a particular fluoroscopic examination, whose exposure rate is 275 mR/hr. what is the approximate radiation exposure for the radiologic staff present in the fluoroscopy room during the examination?

A

6.87 mR

1.5min X 1hr X 275mR
—- —– = 6.87 mR
60min 1 hr

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

If the exposure rate to an individual standing 4.0 m from a source of radiation is 10 mR/hr, what will be the dose received after 20minutes at a distance of 6m from the source?

A

1.48 mR in 20 mins i1/i2 = D2^2/ D1^2
so..
10/x = 36/16
= 4.44 in one hour (60 minutes)
so… divide 4.44 by 3 (since 20min goes into 60min 3x)
final answer = 1.48 mR in 20 minutes

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

fluoroscopic and radiographic exposure switch type

A

dead man type

so it shuts off when the switch is released

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

what cell type has the greatest radiosensitivity in the adult human?

A

lymphocytes

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

Spermatids radiosensitivity to radiation

A

highly sensitive

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

muscle cells radiosensitivity

A

low radiosenstivity

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

nerve cells radiosensitivity

A

least radiosensitive

EXCEPT in fetal life, then they are highly radiosensitive

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

the interaction between ionizing radiation and the target molecule that is MOST likely to occur is the:

A. Direct effect
B. Indirect effect
C. Target effect

A

indirect effect

occurs most frequently with xrays and matter

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

what is the approximate entrance skin exposure (ESE) for the average AP supine abdomen xray? how about AP c-spine?

A

Abdomen: 300 mrad = .35 rad

C-spine: 80 mrad

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

how will x-ray photon intensity be affected if the SID is doubled?

A

the intensity will decrease 4x

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

occupational radiation monitoring is required when it is possible taht the individual might receive more than?

A

1/10th the annual dose limit

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

MONITORING DEVICES COMPONENTS

A

MONITORING DEVICES COMPONENTS

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

Film badges give a read out by

A

the silver halide is ionized by x-ray photons to give a readout

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

Pocket dosimeter, does it contain an ionization chamber?

A

yes

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

TLD’s give readouts by

A

exposing lithium fluoride crystals to ionizing radiation and then heating, these crystals give off a light that is proportional to the amount of radiation received.

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

OSL dosimeters give a read out by

A

exposing aluminum oxide crystals to ionizing radiation and then to a laser, which gives off a light proportional to the amount of radiation received.

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

sources of natural background radiation contributing to whole-body radiation dose include

A 
terrestrial radionuclides (external: cosmic from space and internal: within earths crust)
           and 
internal radionuclides (within our own bodies.. food we ingest)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

irradiation of water molecules within the body and their resulting breakdown is termed

A

radiolysis

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

free radicals result from

A

radiolysis

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

what contributes MOST to occupational exposure

A

compton scatter

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

thompson scatter is another name for

A

classic scatter

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

the x-ray interaction with matter that is responsible for the majority of scattered radiation reaching the IR is

A

compton scatter

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

in photoelectric effect what happens

A

a low energy photon ejects an inner shell electron leaving a space, which is filled from an electron from the above shell

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

with mA increased to maintain intensity, how is the ESE affected as the SSD is increased

A

the ESE increases

since the mA was increased

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

late radiation-induced somatic effects are effects that occur: (when)

A

effects that occur years after initial exposure

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

examples of late radiation-induced somatic effects

A

cataracts
cancer
genetic mutations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

each time an x-ray beam scatters, its intensity at 1m from the scattering objects is what fraction of its original intensity?

A

1/1,000

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

the x-ray beam should scatter ___ times before reaching the operator

A

twice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

annual occupational whole-body dose equivalent limit is?

mSv?
rem?

A

50 mSv

5 rem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

a Thermoluminescent dosimetry (TLD’s) system would use what type of crystal?

A

lithium fluoride

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

sources of secondary radiation include:

A

leakage radiation
and
scattered radiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

leakage radiation is when radiation exits the…

A

tube housing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

background radiation is ____ occurring radiation that is emitted from…

A

natural occurring radiation

that is emitted from the earth and also exists within our bodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

what is used to account for the differences in tissue sensitivity to ionizing radiation when determining effective dose E?

A

tissue weighting factor (Wt)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

the photoelectric effect is more likely to occur with

A

absorbers having a high atomic number (Z number) (heavier weight)
and
positive contrast media (high density, like barium)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

photoelectric effect and patient dose

A

the photoelectric effect is largely responsible for patient dose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

In radiation protection, the product of absorbed dose and the correct modifying factory (rad X QF)is used to determine

A

rem (sV)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

what is the unit of measure that expresses the dose-effect relationship?

A

rem

its the dose equivalent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

what measures dose equivalent

what is its units

A

rem

Sv

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q 
the annual dose limit for medical imaging personnel includes radiation from:
A. occupational exposure
B. background radiation
C. medical X-rays
D. all the above
A

A. occupational exposure only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

what anomaly is possible if an exposure dose of 40 rad (400 mGy) were delivered to a pregnant uterus in the third week of pregnancy?

A

organ anomaly (bc their organs are starting to form)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

what trimester is the fetus most radiosensitive

A

first

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

when would neurologic anomalies be formed in a fetus

A

in the later trimesters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

when can fetal irradiation result in embryonic reabsorption or spontaneous abortion?

A

during the first two weeks of gestation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

BREAK

A

BREAK

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Fractionation

A

if the radiation is delivered in portions over a period of time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

medical and dental radiation accounts for what percentage of the general publics exposure to to HUMAN-MADE radiation?

A

90%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

epithelial tissue radiosensitivity

A

very radiosensitive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

non dividing cells radiosensitivity:

ex. of non dividing cells

A

least radiosensitive

neurons and neuroglia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

how does filtration affect the primary beam

A

it filters out low energy photons which hardens the beam and

increases the average energy of the primary beam

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

what is the minimum lead requirement for lead aprons according to the NCRP

A

.5 mm Pb

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

an optically stimulated luminescence dosimeter contains what component

A

aluminum oxide crystals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

aluminum oxide crystals (used in OSL dosimeters) give a readout that is ___ to the amount of radiation received

A

proportional

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

immature cells examples

A

undifferentiated cells
and
stem cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

Radiosensitivity of:

immature cells:
mature cells:

A

immature: highly sensitive
mature: low sensitivity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

what is the term used to describe x-ray photon interaction with matter AND the transference of part of the photons energy to matter?

A

scatter

key word is PART of the photons energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

the term that describes the reduction in the intensity (quantity) of an x-ray beam as it passes through matter

A

attenuation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

scattering occurs when there is

A

a PARTIAL transfer of the protons energy to matter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

what is the ESE (entrance skin exposure) of a:

chest x-ray:
AP lumbar:

A

chest x-ray: 12 mrad (.012 rad)

AP lumbar: 350 mrad (.35 rad)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

primary radiation barriers must be at least how high?

A

7ft

67
Q

the annual dose limit for occupationally exposed individuals is valid for___ types or radiation

A

x and gamma radiations only

68
Q

patient dose increases as fluoroscopic FOV..

A

decreases

69
Q

FSS stands for

A

focal spot size

70
Q

what unit measures the quantity of ionization in the air

A

Roentgen

71
Q

Rem stands for

A

radiation equivalent man

72
Q

a method of expressing radiation quality can be defined by

A

LET

73
Q

X-rays and gamma rays have what type of LET radiation

A

low

74
Q

the skin response to radiation exposure that appears as hair loss is known as

A

epilation

75
Q

Anoxic:
Hypoxic:

A

Anoxic: without oxygen
Hypoxic: low oxygen

76
Q

tissues are most radiosensitive when they have what type of oxygen levels

A

when they are highly oxygenated

77
Q

which type of dose-response relationship represents radiation-induced leukemia and genetic effects

A

linear, non threshold

78
Q

late effects are also called

A

stochastic effects

79
Q

childhood malignant diseases, such as cancers or leukemia can result from irradiation during what trimester

A

first

80
Q

what is the 10-day rule

A

says that the first 10 days following the onset of a womans period is the safest time to schedule a procedure of the pelvis/abdomen

81
Q

tissues having a ____density absorb more xray beam

A

higher

82
Q

is fat easy or hard to penetrate?

A

easy, along with lungs

83
Q

leakage radiation must not exceed

A

100 mR/hr at 1m

84
Q

screen speeds does what to patient dose

High speed intensifying screens:

Low speed intensifying screens:

A

high speed intensifying screens allows for a lower mAs and therefore a lower patient dose

low speed intensifying intensifying screen needs more mAs and have a higher patient dose

85
Q

what effects both the quality and quantity of the primary beam

A

half value layer
and
kV

86
Q

quality of a beam is from:

quantity of a beam is from:

A

quality: kV, HVL, LET
quantity: mA

87
Q

xrays have high/low

Energy:
LET:
mass:

A

low energy
low LET
no mass

88
Q

primary radiation barriers thickness

secondary radiation barriers thickness

A

primary: 1/16”
secondary: 1/32”

89
Q

which group of exposure factors will deliver the least patient dose?

A. 300 mA, 250 ms, 70 kVp
B. 300 mA, 125 ms, 80 kVp
C. 400 mA, 90 ms, 80 kVp
D. 600 mA, 30ms, 90 kVp

A

D. because it has the lowest mAs and high kVp to decrease the patient dose

90
Q

for radiographic examination of the skull, it is generally preferred that the skull be examined in the _____ projection/position, because____

A

PA since the entrance skin dose is significantly greater than the exit dose.
this way it puts the radiosensitive organs to the IR and away from the primary beam

91
Q

at 1m from the patient, the intensity of the beam is

A

reduced by a factor of 1,000 or

.1% of its original intensity

92
Q

an increase of 1.0 mm added aluminum filtration of the x-ray beam would have what effect

A

increase in average energy of the beam, makes it harder
and
decrease pt dose bc its filtering out low energy photons

93
Q

filtrations job is to

A

remove low energy X-RAY photons to reduce pt dose

94
Q

x-ray photons from the focal spot are what type of beam

A

heterogenous

95
Q

the amount of time that x-rays are being directed toward a particular wall is referred to as

A

use factor

96
Q

the number of x-ray exposures made each week is referred to as

A

workload

97
Q

occupancy factor consists of

A

who occupies particular areas (radiation workers and non radiation workers)

98
Q

radiation effects that appear days or weeks following exposure due to high radiation doses are called

A

acute radiation syndrome

99
Q

acute radiation syndrome is likely to occur if the whole body gets…

A

600 rad at one time

100
Q

hematologic system consists of

A

blood
liver
bone marrow
spleen

101
Q

-penia

A

decrease, lack of

102
Q

first stage of acute radiation syndrome is called:

symptoms are:

A

prodromal

nausea, vomiting, diarrhea, fatigue

103
Q

BREAK

A

BREAK

104
Q

the unit of measurement used to express occupational exposure

A

rem (sV)

105
Q

what is responsible for the dose to biologic material

A

rem (sV) because it includes RBE to tissues

106
Q

bucky slot cover has ___mm Pb

A

.25 mm Pb

107
Q

fluoro mA must not exceed

a timer will time if fluoro is on more than

A

5 mA

5 minutes

108
Q

fluoro protective curtain must contain ____mm Pb

A

.25 mm Pb

109
Q

which type of personnel radiation monitoring device can provide an immediate reading

how:
downfall to this type:

A

ionization chamber: pocket dosimeter or pocket ionization chamber

its like a pen and you hold it up and look through it to see the reading but it doesn’t keep an ongoing count

110
Q

if the ESE for an exposure is 25mrad, what will be the intensity of the scattered beam perpendicular to and 1m from the patient?

A

.025 mrad

25 X 1/1000

111
Q

what factors contribute to scatter PRODUCTION

A

kVp (the higher the kVp the more scatter that is PRODUCED)

field size (larger field, larger amount of scatter produced)

thickness and condition of the tissue (thicker/more dense, more scatter produced)

112
Q

the automatic exposure device that is located immediately under the xray table is the

A

ionization chamber

113
Q

scintillation camera is used in

A

nuclear medicine

114
Q

the law of Bergonie and Tribondeau states that cells are more radiosensitive if they are

A

highly proliferative (highly mitotic)

immature

115
Q

undifferentiated cell

A

immature

116
Q

stem cells

A

immature cells

117
Q

LET and RBE relationships

A

direct

118
Q

which of the following radiation-induced conditions is most likely to have the longest latent period?

leukemia
temporary infertility
acute radiation lethality

A

leukemia

119
Q

late effects aka

A

stochastic
or
genetic effects

120
Q

diagnostic xrays have an RBE of

A

1.0

121
Q

the most radiosensitive portion of the GI tract is

A

small bowel bc its cells are highly mitotic

122
Q

the photoelectric effect is an interaction between an x-ray photon and…

A

an inner shell electron

123
Q

filters used in xray tubes are generally composed of

A

aluminum

124
Q

what kind of radiation is produced at the tungsten target of the xray tube, from the filament

A

brems and characteristic

125
Q

which interaction results in an incident electron which is deflected and results in energy loss?

A

Brems

126
Q

an increase in beam filtration will increase_(what factor)___ and decrease __(what factor)___

A

increase HVL
increase energy

decrease mR output

127
Q

what is used to determine the biologic damage in living tissues

A

RBE

128
Q

the purpose of filters in a film badge is to

A

measure radiation quality (energy) to see what dose the tech is getting

129
Q

which body parts are included in the whole body dose?

which ones are not?

A

Gonads
and
blood forming organs
NOT EXTREMITIES bc they high a higher annual dose limit

130
Q

energy is also referred to as

A

quality of the beam

131
Q

which personnel monitoring devices is said to be the most sensitive and most accurate

A

OSL dosimeter bc it can measure as low as 1mrem

132
Q

a large dose to the whole body all at once is said to be (harmful?)

A

most harmful since the body doesnt have time to repair itself as it would to a large dose to a specific area at one time

133
Q

how much protection is provided from a 100 kVp xray beam when using a .5 mm Pb apron
how about a 50 kVp xray beam at .5 mm Pb apron

A

100 kVp: 75%

50 kVp: 99%

134
Q

local tissue damage is from what effect of ionizing radiation (early, late)

A

late, long term effect unless it happens shortly after exposure

135
Q

red blood cells radiosensitivity

red blood cells are also called

A

very radiosensitive

erythrocytes

136
Q 
the classification of acute radiation syndrome include all of the following except
A. CNS
B. GI tract
C. neonatal
D. hematologic
A

C. neonatal bc acute radiation syndrome is an early somatic effect

137
Q

compton scatter ejects an ___ shell electron

A

outer

138
Q

effective dose refers to

A

whole body dose

139
Q

whole body dose is also referred to as ____ dose

A

effective

140
Q

blood changes short or long term effects

A

short

141
Q

types of secondary radiation barriers include
A. the control booth
B. lead aprons
C. the xray tube housing

A

all of them

because secondary radiation is from scatter and leakage radiation

142
Q

pair production occurs at

A

1.022 MeV

this does not occur in diagnostic xray

143
Q

radiation effects that are during the life of the exposed individual is said to be _____ effects

A

somatic effects

144
Q

radiation effects to the gonads of an exposed individual and are passed on are said to be ____ effects

A

genetic effects

145
Q

the dose that it takes to bring about a noticeable erythema is referred to as _ _ _

A

SED

erythema: reddening of the skin

146
Q

controlled area vs uncontrolled area

A

controlled: means the area may always be occupied, by radiation workers and requires maximum shielding, must not exceed 100mR/week
uncontrolled: occupied by the general public, must not exceed 10mR/week

147
Q 
periods of time:
gestation:
congenital:
neonatal:
in vitro:
in vivo:
A

gestation: pregnancy
congenital: condition that exists at birth
neonatal: from birth thru the first month of life
in vitro: living outside a living body (in a test tube)
in vivo: within a living system

148
Q

somatic effects are (early or late) effects

A

both, depending on the time they manifest effects

149
Q

BREAK

A

BREAK

150
Q

stochastic effects (early or late)

A

late

151
Q

“all or nothing” effects

A

stochastic

either the organ develops cancer or it doesn’t

152
Q

when would a radiographer be required to wear 2 dosimeters?

A

when they are pregnant
or
when performing a vascular procedure

153
Q

how much radiation to the reproductive organs can cause temporary infertility? what about permanent sterility?

A

temporary infertility: 200 rad

sterility: 500 rad

154
Q

table top exposure rate during fluoro shall not exceed

A

10 R/min

155
Q

radiation induced skin erythema has what kind of curve?

A

non linear, threshold

156
Q

alpha particle consists of

A

2 protons and 2 neutrons

157
Q

beta particle is composed of

A

an electron

158
Q

radiation output is measured in

A

roentgen: ionization in air.. the output hits air

159
Q

becqueral measures

A

radioactivity

160
Q

the interaction between xray photons and tissue that is responsible for radiographic contrast is

A

photoelectric effect

also contributes significantly to pt dose

161
Q

lead aprons should be checked for cracks…(how often)

A

yearly

162
Q

what theory relates to DNA

A

target theory

163
Q

radon is found

A

in the earth
and
in houses
and cigarettes

164
Q

quality factor is also called

A

RBE

Registry Review (3 decks)

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