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PMP I FINAL > Radiology I- Radiologic Physics, Radiation Protection & Biology > Flashcards

Radiology I- Radiologic Physics, Radiation Protection & Biology Flashcards

1
Q

According to the law of Bergonie and Tribondeau, living tissues with high radio sensitivity include:

A
  • cells with high metabolic activity

- tissues with high growth rate

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2
Q

T/F the most critical time for irradiation of a fetus is during the first two weeks of gestation

A

TRUE

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3
Q

T/F in a linear, non-threshold dose-response relationship, any dose, regarding of its size, is expected to produce a response.

A

TRUE

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4
Q

T/F The radiolysis of water results in the formation of free radicals but not ions.

A

FALSE

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5
Q

T/F It is not necessary to return the control film badge at the end of each month when returning the personnel film badges to the radiation dosimetry company.

A

FALSE

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6
Q

Protective barrier thickness is determined by the:

A
  • distance between the radiation source and the barrier
  • number of examinations performed per week (workload)
  • penetrability of the x-ray beam
  • time of occupancy of the area
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7
Q

a free radical

A

is highly active

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8
Q

T/F primary protective barriers are mainly used to shield areas from scatter and leakage radiation

A

FALSE

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9
Q

When water is irradiated, it dissociates into other molecular products. this action is known as:

A

radiolysis

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10
Q

an example of primary radiation is

A

the useful beam

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11
Q

T/F human cells aren’t capable of recovering from radiation damage.

A

FALSE

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12
Q

ways to reduce unnecessary pt dose include:

A
  • eliminate repeat exams

- position glands out of the primary beam

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13
Q

T/F compared to using an appropriate kVp technique and appropriate film-screen combination, lowering kVp and selecting a slower speed film-screen combination will increase the pt’s dose.

A

TRUE

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14
Q

T/F as the proliferation rate for cells and the growth rate for tissues decrease, the radio sensitivity decreases also.

A

TRUE

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15
Q

T/F lead aprons and gloves should be folded and placed flat on a shelf.

A

FALSE

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16
Q

the unit of dose equivalent or occupational exposure that is used to express the quantity of radiation received by a radiation worker is known as the:

A

rem

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17
Q

the most radiosensitive macromolecule is

A

DNA

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18
Q

precautions to take before or during radiography on a pregnant pt include:

A
  • document
  • collimate
  • shield
  • high kVp technique
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19
Q

cardinal principles of radiation protection include:

A
  • minimize time
  • maximize distance
  • maximize shielding
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20
Q

fetal congenital abnormalities will most likely occur if the fetus is irradiated during the:

A

3-8 wks

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21
Q

T/F radiation-induced malignancy and genetic effects are late effects of low-dose radiation over long periods of time

A

TRUE

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22
Q

T/F secondary barriers are used to shield against the useful beam

A

FALSE

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23
Q

scatter radiation is increased by:

A
  • increasing the field size

- thicker body parts

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24
Q

a material used as a primary barrier is

A

concrete

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25
Q

reduction of unnecessary pt dose can be achieved by:

A

collimating the area in question

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26
Q

a cardinal principal of radiation protection is to minimize:

A

time

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27
Q

a measure of the rate at which energy is transferred from ionizing radiation to soft tissue is known as:

A

linear energy transfer

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28
Q

an early effect of radiation on humans is:

A

skin erythema

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29
Q

of the following, the cell type that has the highest radio sensitivity is the:

A

lymphocyte

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30
Q

T/F a free radical is a charged molecule containing a single unpaired electron in the valence or outermost shell

A

FALSE

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31
Q

T/F a film badge (or, personnel monitor) is properly worn at chest level

A

TRUE

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32
Q

T/F The 3 principal observable effects resulting from irradiation of DNA include cell death, malignant disease, and genetic damage.

A

TRUE

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33
Q

T/F free radicals cause damage by the direct effect of radiation.

A

FALSE

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34
Q

the principle observable effects resulting from irradiation of DNA include:

A
  • cell death
  • malignant disease
  • genetic damage
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35
Q

T/F the delayed or late effects of radiation can follow low doses delivered over a long time period.

A

TRUE

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36
Q

T/F biologic tissue is more sensitive to radiation when irradiated in the oxygenated (aerobic) state.

A

TRUE

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37
Q

T/F a measure of the rate at which energy is transferred from ionizing radiation to soft tissue is known as linear energy transfer

A

TRUE

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38
Q

T/F a podiatric assistant should be used to hold an infant during an x-ray procedure, not the parent

A

FALSE

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39
Q

T/F when the level of metabolic activity is low, radio sensitivity is high

A

FALSE

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40
Q

T/F research has shown, on avg, that a full-time radiographer’s life-span is shortened by 4 years.

A

FALSE

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41
Q

the following dose-response relationship has been adopted as the model for establishing radiation protection guidance:

A

linear non-threshold

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42
Q

T/F major effects of macromolecule irradiation include main-chain scission, cross-linking, and point lesions.

A

TRUE

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43
Q

the unit of radiation measurement that is used to describe the radiation quantity or dose absorbed by the pt is known as the:

A

rad (gray)

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44
Q

T/F a free radical can join with a similar molecule and form hydrogen peroxide which is poisonous to the cell

A

TRUE

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45
Q

If an undetected pregnant pt is irradiated, the:

A

fetal dose should be estimated

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46
Q

T/F lead-lined barriers are required for secondary protective barriers.

A

FALSE

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47
Q

the least radiosensitive macromolecule of the following is:

A

protein

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48
Q

T/F the dose-response relationship for radiation-induced cataracts is apparently threshold, non-linear

A

FALSE

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49
Q

a cell type that exhibits high radio sensitivity to ionizing radiation is:

A

lymphocyte

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50
Q

of the following, the organ or tissue that has the highest radio sensitivity is:

A

gonad

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51
Q

T/F the principle action of radiation on humans is by the direct effect.

A

FASLE

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52
Q

T/F ALARA stands for as large as reasonable achievable.

A

FALSE

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53
Q

T/F a pregnant radiographer should wear an additional personal monitoring device under her apron at waist level.

A

TRUE

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54
Q

if an infant needs to be held still during a radiographic study, it should be done by the

A

guardian or parent

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55
Q

barriers are used to shield against:

A
  • the useful beam
  • leakage radiation
  • scatter radiation
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56
Q

T/F MPD (max permissible dose) is defined as the max dose of radiation expected to produced significant radiation effects.

A

FALSE

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57
Q

T/F the age of a biologic structure affects its radiosensitivity

A

TRUE

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58
Q

The pregnant radiographer should:

A

have her previous radiation exposure history reviewed

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59
Q

T/F the late effect of radiation is defined as follows: the radiation response occurs within minutes or days after radiation exposure.

A

FALSE

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60
Q

T/F the law of Bergonie and Tribondeau states the following: tissues that are younger, have a high level of metabolic activity, and have a high growth rate are more radiosensitive.

A

TRUE

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61
Q

according to the Law of Bergonie and Tribondeau:

A

radio sensitivity increases with increasing tissue growth rate

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62
Q

the effects of proper collimation are:

A
  • reduce pt dose

- improve image contrast

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63
Q

T/F the damage caused by free radicals as they transfer their energy to a target molecule occurs by the direct effect of radiation.

A

FALSE

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64
Q

T/F if the initial ionizing event occurs on the molecule that is irradiated, the effect is said to be indirect

A

FALSE

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65
Q

regarding radiation-protection design for x-ray equipment:

A

the output radiation intensity should be constant from one exposure to the next

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66
Q

T/F one factor that barrier thickness depends on is the distance bw the radiation source and the barrier

A

TRUE

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67
Q

T/F an infant should be held still during the exposure b the radiographer, not the parent or guardian.

A

FALSE

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68
Q

T/F a cardinal principle of radiation protection is to maintain a large distance bw the body part and the film

A

TRUE

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69
Q

T/F a cardinal principle of radiation protection is to keep the time of radiation exposure long

A

FALSE

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70
Q

T/F radiation dose-response relationships are used to design therapeutic treatment routines for pts with cancer and to provide info on the effects of low-dose irradiation.

A

TRUE

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71
Q

T/F the linear, non-threshold dose-response relationship states that a specific irradiation dose is necessary to produced a response in tissue .

A

FALSE

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72
Q

the biologic effectiveness of radiation energy absorbed is measured by the:

A

rem

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73
Q

protective barrier thickness is determined by the:

A

all of the above answers are correct

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74
Q

T/F generally speaking, the older tissues and organs are, the less radiosensitive they are:

A

TRUE

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75
Q

T/F fetal exposure of radiation drink the first week of pregnancy will most likely result in skeletal deformities.

A

FALSE

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76
Q

an uncharged molecule containing a single unpaired electron in the outermost shell is known as a(n):

A

free radical

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77
Q

according to the law of Bergonie and Tribondeau, living tissues with high radiosenstivity include:

A
  • cells with high metabolic activity

- tissues with high growth rate

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78
Q

T/F the film badge control monitor should be kept in the radiography procedure room

A

FALSE

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79
Q

T/F free radicals are formed by the radiolysis of water

A

TRUE

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80
Q

most states recommend that the film badge be worn at the level of the:

A

collar

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81
Q

consider the following 2 characteristics: 1) any radiation dose, regardless of its size, is expected to produce a response; and 2) the response to radiation is directly proportional to the dose. This is known as the:

A

linear non threshold relationship

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82
Q

a disadvantage of the film badge is its:

A

sensitivity

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83
Q

T/F film badges are inexpensive and reasonably accurate. However, they are sensitive to heat and humidity.

A

TRUE

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84
Q

T/F the required thickness of a lead apron is 0.25 mm

A

TRUE

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85
Q

T/F free radicals contain excess energy that can be transferred to other molecules to disrupt bones and produce pt lesions at some distance from the initial ionizing event

A

TRUE

86
Q

T/F the linear, non threshold relationship can be described as follows: only high radiation doses will be expected to produce a response in human tissues.

A

FALSE

87
Q

T/F according to the law of Bergonie and Tribondeau, radio sensitivity is a function of the metabolic tissue being irradiated

A

TRUE

88
Q

T/F The disadvantage of a protective lead apron with higher lead equivalent thickness is that it attenuates more x-rays

A

FALSE

89
Q

T/F stem cells are radiosensitive

A

TRUE

90
Q

T/F epidemiological studies of ppl exposed to radiation are easily obtained because the does are known and the frequency response is high

A

FALSE

91
Q

T/F x-rays and gamma rays are examples of particulate radiation

A

FALSE

92
Q

the x-ray tube housing:

A
  • reduces leakage radiation
  • protects against accidental electrical shock
  • contains oil that serves as a thermal cushion
93
Q

T/F a 70 keV x-ray photon has higher energy than a 50 keV photon

A

TRUE

94
Q

T/F the term “quantity” refers to the penetrating ability of the x-ray beam

A

FALSE

95
Q

T/F classical scattering is of little importance to diagnostic radiology because it primarily involves low-energy x-rays which contribute little to the raidograph

A

TRUE

96
Q

the cathode

A
  • is composed of the filament

- is composed of the focusing cup

97
Q

T/F the production of x-rays that results from the braking of projectile electrons by the target nucleus is known as characteristic radiation

A

FALSE

98
Q

the exposure factors for a radiographic study of the ankle are 15 mA and 0.5 seconds. in order to obtain the same film density at 10 mA, the new time setting would be (assume that all other factors remain unchanged):

A

0.75 seconds

99
Q

T/F classical scatter occurs when the x-ray photon changes direction, loses energy, and ionizes an atom

A

FALSE

100
Q

line A is an initial x-ray emission spectrum. By decreasing ______, line B will result.

A

kVp

101
Q

T/F generally speaking, approximately 99% of the kinetic energy of projectile electrons traveling between the cathode and anode is converted into x-rays

A

FALSE

102
Q

an x-ray photon is totally absorbed and an inner shell electron is ejected during ionization. this describes:

A

photoelectric effect

103
Q

T/F the half-value layer of an x-ray beam refers to the thickness of absorbing material necessary to reduce the x-ray intensity to half of its original value.

A

TRUE

104
Q

T/F the inverse square law states that the intensity of the x-ray beam is directly proportional to the square of the distance between the object and the source

A

FALSE

105
Q

the 2 mechanisms of x-ray production are:

A
  • bremsstrahlung

- characteristic

106
Q

T/F Photoelectric and Compton are ways that x-rays interact with matter, not how they are produced

A

TRUE

107
Q

the photoelectric effect:

A
  • more likely occurs with inner shell electrons

- plays an important role in image formation

108
Q

T/F a purpose of the x-ray tube housing is to absorb off focus radiation

A

TRUE

109
Q

T/F a compensation filter is permanently installed inside the tube head.

A

FALSE

110
Q

T/F differential absorption of x-rays is dependent upon atomic number and mass density

A

TRUE

111
Q

the half-value layer is defined as the thickness of absorbing material necessary to reduce the x-ray intensity to ______ its original value.

A

one-half

112
Q

T/F photons that have long wavelengths have high energy

A

FALSE

113
Q

T/F differential absorption of x-rays depends on atomic number and mass density

A

TRUE

114
Q

Variable that can be manipulated on the control panel include:

A
  • kVp
  • mA
  • time
115
Q

According to the quantum theory, photon energy is:

A

directly proportional to photon frequency & inversely proportional to photon wavelength.

116
Q

T/F photons interact with matter most easily when matter is approximately the same size as the photon wavelength

A

TRUE

117
Q

T/F if the kVp setting of an x-ray unit is set at 60, then only x-rays having 60 keV energy are being emitted from the x-ray tube

A

FALSE

118
Q

T/F increasing the kVp causes the x-ray emission spectrum to shift to the higher energy side

A

TRUE

119
Q

Examples of ionizing electromagnetic radiation include:

A
  • x-rays

- gamma rays

120
Q

T/F aluminum added filtration results in an x-ray beam that has an increased effective energy

A

TRUE

121
Q

T/F rad/gray is the unit of ionizing radiation used to express the quantity of radiation received by radiation workers

A

FALSE. correct answer is rem/sievert

122
Q

T/F at the anode, only a small amount of the KE of projectile electrons is converted into heat.

A

FALSE

123
Q

the 2 forms of x-ray interactions with matter most applicable to diagnostic radiology are:

A
  • photoelectric absorption

- Compton scatter

124
Q

T/F generally, more than 99% of the KE of projectile electrons is converted to heat, which leaves less than 1% available for the production of x-rays.

A

TRUE

125
Q

T/F the sheet of aluminum located between the tube housing and collimator is known as inherent filtration

A

FALSE

126
Q

an x-ray:

A
  • travels at the speed of light
  • has frequency and wavelength that are inversely related
  • has no mass and no charge
127
Q

the type of x-ray interaction with matter that is important for image formation by producing high contrast but leads to a high absorbed patient dose is known as

A

photoelectric absorption

128
Q

T/F the primary purpose of the oil surrounding the x-ray tube is to cushion the tube so it doesn’t break during positioning of the tube head.

A

FALSE

129
Q

The x-ray interactions with matter that are applicable to diagnostic radiology are:

A
  • Compton scattering

- photoelectric effect

130
Q

T/F Bremsstrahlung radiation refers to formation of x-rays, not interaction with matter, which Compton scatter and photoelectric effect both refer to

A

TRUE

131
Q

The following type of x-ray does NOT contribute positively to image formation

A

Compton scattering

132
Q

T/F during x-ray production, an intense ant of heat is generated at the cathode.

A

FALSE

133
Q

energy emitted and trasnferred through matter is known as:

A

radiation

134
Q

T/F x-rays undergo radioactive decay

A

FALSE

135
Q

T/F the Compton-scattered x-ray contributes no useful information to the radiograph

A

TRUE

136
Q

T/F a photon is the smallest quantity of electromagnetic radiation

A

TRUE

137
Q

in the x-ray tube, x-rays are produced at the

A

anode

138
Q

the Compton-scattered x-ray contributes no useful information to the radiograph

A

TRUE

139
Q

The anode includes the

A

target

140
Q

T/F regarding the “heel effect,” radiation intensity on the anode side of the x-ray field is lower than that on the cathode side

A

TRUE

141
Q

T/F attenuation is defined as total absorption of energy

A

FALSE

142
Q

from the following choices, the form of electromagnetic radiation that has the shorted wavelength is

A

x-rays

143
Q

the sheet of aluminum found between the protective tube housing and the collimator is known as

A

added filtration

144
Q

T/F added filtration has no effect on the x-ray emission spectrum

A

FALSE

145
Q

T/F x-ray photons have no mass, no charge, and travel at the speed of light

A

TRUE

146
Q

the negative en dog the x-ray tube is the:

A

cathode

147
Q

T/F characteristic x-rays can be produced if the projectile electron interacts with an inner shell electron of the target atom rather than with the outer shell electron

A

TRUE

148
Q

_____ are emitted from the nucleus of a radioisotope

A

gamma rays

149
Q

the following type of filtration is placed along the outer surface of the collimator:

A

compensation

150
Q

an increase in ___ will NOT cause the x-ray emission spectrum to shift to the right

A

mA

151
Q

T/F regarding the heel effect, the radiation intensity on the cathode side of the x-ray field is higher than that on the anode side

A

TRUE

152
Q

factors that can be manipulated on a lower extremity-specific radiography unit include:

A

kVp, mA, time

153
Q

T/F anatomic structures with high x-ray absorption characteristics are referred to as radiolucent

A

FALSE

154
Q

ionizing radiation has:

A

high energy, short wavelength

155
Q

the wavelength of the x-ray photon is controlled by the

A

kilovoltage

156
Q

T/F more than 99% of the KE of projectile electrons is converted into thermal radiation

A

TRUE

157
Q

if the source to obj distance is decreased from 30 in to 15 in, then the radiation intensity which originally was 8 would now be

A

32

I1/I2=[d2/d1]^2

158
Q

any wall to which the useful x-ray beam can be directed is designated a(n):

A

primary barrier

159
Q

the purpose of the x-ray tube housing is:

A

to absorb off-focus radiation

160
Q

_____are produced outside the nucleus in the electron cloud

A

x-rays

161
Q

factors that affect the x-ray image’s optical density include:

A

mA and kVp

162
Q

you are presently using an exposure technique of 10 mA and 1/2 second with a particular x-ray imaging system. you decide to increase the mA in order to reduce the effect of patient movement on the final image. assuming all other factors remain unchanged, determine the new exposure time using 15 mA

A

1/3 second

163
Q

T/F high energy x-rays have longer wavelength than low energy x-rays.

A

FALSE

164
Q

characteristic of x-rays include

A

ionizing

165
Q

Bremsstrahlung radiation results:

A

when a projectile electron slows and changes course as it passes the target atom’s nucleus

166
Q

T/F characteristic x-rays can be produced if the projectile electron interacts with an outer shell electron of the target atom rather than with the inner shell electron

A

FALSE

167
Q

T/F a 15% increase in mA is equivalent to doubling the kVp

A

TRUE

168
Q

At lower energies of x-radiation:

A
  • pt dose increases

- photoelectric interactions increase

169
Q

Bremsstrahlung radiation occurs when:

A

a projectiel electron is slowed down

170
Q

T/F x-rays are produced at the cathode side of the tube

A

FALSE

171
Q

T/F approximately 99% of the KE of projectile electrons in the x-rya tube is converted to x-radiation

A

FALSE

172
Q

T/F the x-ray tube current, the number of electrons crossing the cathode to anode, is measured in kilovorlts

A

FALSE

173
Q

the intensity of the x-ray beam is 4 mAs at a distance of 20 inches from the source. What is the intensity of the same x-ray beam at a distance of 40 inches from the source?

A

1 mAs

174
Q

T/F Generally speaking, if the distance doubles, the intensity will be cut to 1/4

A

TRUE

175
Q

T/F if all other factors remain unchanged, increasing the source to image distance will decrease the intensity of the x-ray beam at the subject

A

TRUE

176
Q

the Compton effect:

A
  • changes the x-ray photon direction
  • ionizes the target atom
  • reduces photon energy
177
Q

T/F added filtration absorbs the high energy x-rays that would otherwise be absorbed by the patient

A

FALSE

178
Q

T/F differential absorption of x-rays increases as the kVp is lowered

A

TRUE

179
Q

T/F Compton scatter occurs when the incident x-ray photon is totally absorbed, the atom is ionized, and secondary x-rays are produced

A

FALSE

180
Q

Differential attenuation (absorption) of the x-ray is dependent on the subject:

A
  • density
  • thickness
  • atomic number
181
Q

T/F the interaction bw low energy x-rays and atoms that results in the scattering of the original, incident x-ray such that is doesn’t lose energy or change wavelength is known as the Compton effect

A

FALSE

182
Q

sources of natural radiation include:

A

cosmic rays and radon

183
Q

T/F the radioactive half-life of an x-ray is approximately 2 sec

A

FALSE

184
Q

the x-ray tube target is made of

A

Tungsten

185
Q

the heel effect

A

results in smaller effective focal spot and less radiation intensity on anode side of x-ray beam

186
Q

T/F attenuation is defined as the total reduction in the number of x-ray s remaining in an x-ray beam following penetration through a given thickness of matter

A

TRUE

187
Q

portions of the electromagnetic spectrum important to diagnostic imagine include:

A
  • x-ryas
  • visible light
  • radio waves
188
Q

the primary factor that influences x-rays quantity is:

A

mAs

189
Q

T/F the primary purpose of a collimator is to reduce the pt dose by restricting the volume of the tissue irradiated

A

TRUE

190
Q

the x-rays that provide the most diagnostic info to the image receptor because they are differentially absorbed are produced by the:

A

photoelectric effect

191
Q

factors that can influence x-ray quantity include:

A
  • kVp
  • mAs
  • added filtration
192
Q

the following is/are NOT a source of natural ionizing radiation:

A

x-rays

193
Q

the smallest quantity of any type of electromagnetic radiation is the:

A

photon

194
Q

the standard SID for your wall-mounted lower extremity x-ray unit with flexible arm is 28 inches. however, this unit is not easily positioned, and the assistant inadvertently positions the SID at 32 inches. if all other technical factors (mA, time, kVp) remain unchanged, the resultant radiograph will have an optical density that is:

A

less black

195
Q

according to the inverse square law, if the radiation intensity at a 40 inch SID is 2 Roentgen (R), then the radiation intensity at a 20 inch SID will be:

A

8R

196
Q

a filter that is placed along the outside of the collimator and is used to adjust for differences in film density due to varying tissue thicknesses is known as:

A

a compensating filter

197
Q

the amplitude of the x-ray emission spectrum is affected by changes in:

A
  • mA
  • kVp
  • added filtration
198
Q

the x-ray interaction with matter that results in ionization of the target atom and scatters the photon is known as:

A

the Compton effect

199
Q

electromagnetic radiation with the shortest wavelength

A

x-rays

200
Q

factors that affect x-ray quality include:

A

filtration & kV

201
Q

T/F mAs only affects the quantity or number of x-ray photons; filtration and kV additionally influence the energy of the beam, i.e. its penetrability (or quality)

A

TRUE

202
Q

T/F the heel effect causes radiation intensity on the anode side of the x-ray beam to be higher than on the cathode side

A

FALSE

203
Q

T/F the half-value layer of an z-ray beam refers to the thickness of absorbing material necessary to decrease the x-ray intensity to half its original value

A

TRUE

204
Q

T/F Bremsstrahlung x-rays are produced when a projectile electron interacts with an inner shell electron and removes it

A

FALSE

205
Q

T/F x-rays have a longer a longer wavelength than visible light

A

FALSE

206
Q

T/F ionization is the process whereby a proton is removed from a target atom

A

FALSE

207
Q

T/F Bremsstrahlung radiation is produced following the ionization of an electron

A

FALSE

208
Q

T/F Bremsstrahlung x-rays demonstrate a discrete x-ray emission spectrum, that is, x-rays with precisely fixed energies

A

FALSE

209
Q

factors that can affect x-ray quantity include:

A
  • mAs
  • kV
  • filtration
210
Q

the types of x-rays that are important in making the radiograph include:

A
  • those transmitted through the pt without interaction
  • those scattered by Compton interaction
  • those absorbed photoelectrically
211
Q

x-rays demonstrate all of the properties of light waves except:

A

reflection

212
Q

primary factors that affect x-ray quality include:

A

kvp and filtration

PMP I FINAL (5 decks)

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