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Lange Ch. 3
Question | Answer |
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101. Which of the following ionizing radiations is described as having an RBE of 1.0 ? | Diagnostic x-rays |
102. If an individual receives 50 mR while standing 4 ft. from a source of radiation for 2 min., which of the following option(s) will most effectively reduce his or her radiation exposure to that source of radiation? | Standing 8 ft. from the source for 2 mins. |
103. An optically stimulated luminescence dosimeter contains which of the following detectors? | Aluminum oxide |
104. How do fractionation and protraction affect radiation dose effects? | They reduce the effect of radiation exposure, they permit cellular repair, they allow tissue recovery |
105. The photoelectric effect is an interaction between an x-ray photon and | an inner-shell electron |
106. Filters used in radiographic x-ray tubes generally are composed of | aluminum |
107. All of the following function to reduce patient dose, except | a high-speed grid |
108. In the production of Bremsstrahlung radiation | the incident electron is deflected, with resulting energy loss |
109. All of the following radiation-exposure responses exhibit a nonlinear threshold dose-response relationship, except | leukemia |
110. Which of the following may be used to express exposure in air? | Gy |
111. The purpose of filters in a film badge is | to measure radiation quality |
112. How many HVLs are required to reduce the intensity of a beam of monoenergetic photons to less that 15% of its original value? | 3 |
113. Which of the following has (have) an effect on the amount and type of radiation-induced tissue damage? | quality of radiation, type of tissue being irradiated, fractionation |
114. Radiation dose to personnel is reduced by which of the following exposure control cord guildlines? | Exposure cords on fixed equipment must be very short, exposure cords on mobile equipment should be fairly long |
115. Primary radiation barriers must be at least how high? | 7 ft. (2.1 m) |
116. Which of the following body parts is/are included in whole-body dose? | gonads, blood-forming organs |
117. Which of the following projections would deliver the largest thyroid dose? | AP skull |
118. Which of the following personnel monitoring devices used in diagnostic radiography is considered to be the most sensitive and accurate? | OSL dosimeter |
119. Irradiation of macromolecules in vitro can result in | cleaved chromosome, cross-linking, mutation |
120. Which of the following radiation situations is potentially the most harmful? | a large dose to the whole body all at one time |
121. How much protection is provided from a 100-kVp x-ray beam when using a 0.50-mm lead equivalent apron? | 75% |
122. Occupational radiation monitoring is required when it is likely that an individual will receive more than what fraction of the annual dose limit? | (1/10) |
123. The interaction illustrated in figure 3-5 (pg. 140) | can pose a safety hazard to personnel, can have a negative impact on image quality |
124. Biologic material is least sensitive to irradiation under which of the following conditions? | anoxic |
125. Which of the following cells are the most radiosensitive? | erythroblasts |
126. Which of the following statements regarding the pregnant radiographer is are/true? | she should declare her pregnancy to her supervisor, she should be assigned a second personnel monitor, her radiation history should be reviewed |
127. Effects of deoxyribonucleic acid (DNA) irradiation include | mitotic delay, reproductive death, chromosome breakage |
128. Which of the following contributes most to the patient dose? | the photoelectric effect |
129. Which of the following statements is/are true with respect to the dose-response curve shown in figure 3-6? | The quantity of radiation is directly related to the dose received, a minimum amount of radiation is required for manifestation of effects |
130. The classifications of acute radiation syndrome include all of the following, except | neonatal |
131. In the production of characteristic radiation at the tungsten target, the incident electron | ejects an inner-shell tungsten electron |
132. Which of the following defines the gonadal dose that, if received by every member of the population, would be expected to produce the same total genetic effect on that population as the actual doses received by each of the individuals? | genetically significant dose |
133. If an exposure dose of 1.5 mGy/h is delivered from a distance of 3 ft, what would be the dose delivered after 20 mins at a distance of 5 ft. from the source? | 0.18 mGy |
134. The term effective dose refers to | whole-body dose |
135. Which of the following is/are possible long-term somatic effects of radiation exposure? | cataractogenesis, embryologic effects |
136. The operation of personal radiation monitoring can be based on stimulated luminescence. Which of the following personal radiation monitors function(s) in that manner? | OSL dosimeter, TLD |
137. If a patient received 0.014 Gy during a 7-min fluoroscopic examination, what was the dose rate? | 0.002 mGy/min |
138. The least radiosensitive stage of human cell mitosis is | S |
139. Which interaction between ionizing radiation and the target molecule involves formation of a free radical? | indirect effect |
140. The single most important scattering object in both radiography and fluoroscopy is the | patient |
141. All of the following statements regarding TLDs are true except | after x-ray exposure, TLDs emit heat in response to stimulation by light |
142. A student radiographer who is younger than 18 years must not receive an annual occupational dose of greater than | 1mSv |
143. Sources of medical radiation exposure include | computed tomography |
144. Which of the following is/are likely to improve image quality and decrease patient dose? | beam restriction |
145. Protective devices such as lead aprons function to protect the user from | scattered radiation |
146. Which of the following radiation protection concepts/measures apply to mobile radiography? | The radiographer should be at least 6 ft. from the patient and the x-ray tube during the exposure, the least amount of scattered radiation is perpendicular to the scattering object, at least one lead apron should be assigned to each mobile unit |
147. Examples of late efforts of ionizing radiation on humans include | leukemia, local tissue damage, malignant disease |
148. Which of the following can be an effective means of reducing radiation exposure? | barriers, distance, time |
149. The effects of radiation on biologic material depend on several factors. If a large quantity of radiation is delivered to a body over a short period of time, the effect | will be greater than if it were delivered in increments |
150. Which of the following cell types has the greatest radiosensitivity in the adult human? | lymphocytes |
151. What minimum total amount of filtration (inherent plus added) is required in x-ray equipment operated above 70 kVp? | 2.5 - mm Al equivalent |
152. The dose of radiation that will cause a noticeable skin reaction is referred to as the | SED |
153. What is the intensity of scattered radiation perpendiculat to and 1 m from a patient compared with the useful beam at the patient's surface? | 0.1% |
154. Some patients, such as infants and children, are unable to maintain the necessary radiographic position without assistance. If mechanical restraining devices cannot be used, who of the following should be the first choice to help immobilizethepatient | Patient's father |
155. A controlled area is defined as one | that is occupied by people trained in radiation safety, that is occupied by people who wear radiation monitors, whose occupancy factor is 1 |
156. Which of the following terms refers to the period between conception and birth? | gestation |
157. Somatic effects resulting from radiation exposure can | have possible consequences on the exposed individual, cause temporary infertility |
158. If the image intensifier is moved farther from the patient | SID increases |
159. In which type of monitoring device do photons release electrons by their interaction with air? | Pocket dosimeter |
160. The advantages of beam restriction include which of the following? | less scattered radiation is produced, less biologic material is irradiated |
161. The person responsible for ascertaining that all radiation guidelines are adhered to and that personnel understand and use radiation safety measures is the | radiation safety officer |
162. The dose- response curve that appears to be valid for genetic and some somatic effects is the | linear, nonthreshold |
163. Which of the following statements regarding the human gonadal cells is/are true? | The female oogonia reproduce only during fetal life, the male spermatogonia reproduce continuously |
164. With milliampers (mA) increased to maintain output intensity, how is the ESE affected as the source-to-skin distance (SSD) is increased? | The ESE decreases |
165. The primary function of filtration is to reduce | patient skin dose |
166. Which of the following factors can affect the amount or the nature of radiation damage to biologic tissue? | radiation quality, absorbed dose, size irradiated area |
167. Examples of stochastic/probabilistic effects of radiation exposure include | radiation-induced malignancy, genetic effects, leukemia |
168. Which of the following tissues is/are considered to be particularly radiosensitive? | intestinal mucous membrane |
169. Which of the following groups of technical factors will deliver the least amount of exposure to the patient? | 400 mA, 0.25 s, 100 kVp |
170. If the exposure rate to an individual standing 4.0 m from a source of radiation is 0.7 mGy/h, what will be the dose received after 20 min at a distance of 6 m from the source? | 0.103 mGy/h |
171. Which of the following projections is most likely to deliver the largest dose to the ovaries? | AP lumbar spine, 14 x 17 in. IR, 80 kVp |
172. Under what circumstances a radiographer might be required to wear two dosimeters? | during pregnancy, while performing vascular procedures |
173. What quantity of radiation exposure to the reproductive organs is required to cause temporary infertility? | 2 Gy |
174. Which of the following personnel radiation monitors will provide an immediate reading? | Pocket dosimeter |
175. Biologic material irradiated under hypoxic conditions is | less sensitive than when irradiated under oxygenated conditions |
176. Which of the dose-response curves shown in Figure 3-7 is representative of radiation-induced skin erythema? (pg. 146) | Dose-response curve C |
177. If the exposure rate at 91 cm from the fluoroscopic table is 1.5 mGy/h, what will be the exposure rate for 30 min at a distance of 152cm from the table? | 0.27 mGy |
178. Lead aprons are worn during fluoroscopy to protect the radiographer from exposure to radiation from | Compton scatter |
179. Radiation that passes through the tube housing in directions other than that of the useful beam is termed as | leakage radiation |
180. The presence of ionizing radiation may be detected in which of the following ways? | Ionizing effect on air, photographic effect on film emulsion, fluorescent effect on certain crystals |
181. Possible responses to irradiation in utero include | spontaneous abortion, congenital anomalies, childhood malignancies |
182. What should be the radiographer's main objective regarding personal radiation safety? | To keep personal exposure as far below the dose limit as possible |
183. Referring to the nomogram in Figure 3-8, what is the approximate patient ESE from a particular projection made at 105 cm using 110 kVp, 300 mA, 5ms, and 2.5 mm Al total filtration? (pg. 147) | 18 mGy |
184. If the exposure rate to a body standing 7 ft. from a radiation source is 1.5 mGy, what will be the dose to that body at a distance of 8 ft from the source in 30 min? | 0.57 mGy |
185. Which of the following types of radiation is/are considered electromagnetic? | x-ray, gamma |
186. Which of the following features of fluoroscopic equipment is/are designed especially to eliminate unnecessary radiation exposure to the patient and/ or personnel? | bucky slot cover, exposure switch/foot pedal, cumulative exposure timer |
187. Radiation output from a diagnostic x-ray tube is measured in which of the following units of measurement? | air kerma |
188. Which of the following is/are considered especially radiosensitive tissues? | bone marrow, intestinal crypt cells, erythroblasts |
189. Which of the following safeguard is/are taken to prevent inadvertent irradiation in early pregnancy? | patient postings, patient questionnaire, elective booking |
190. The interaction between x-ray photons and tissue that is responsible for radiographic contrast but that also contributes significantly to patient dose is | the photoelectric effect |
191. Which of the following is/are acceptable way(s) to monitor the radiation exposure of those who are occupationally employed? | TLD, OSL dosimeter |
192. The genetic dose of radiation borne by each member of the reproductive population is called the | genetically significant dose |
193. According to the NCRP, the pregnant radiographer's gestational dose-equivalent limit for a 1-month period is | 0.5 mSV |
194. What percentage of the SID must the collimator light and actual irradiated area be accurate? | 2% |
195. The correct way(s) to check for cracks in lead aprons is/are | to fluoroscope them once a year |
196. The target theory applies to | DNA molecules |
197. Which of the following is/are features of fluoroscopic equipment designed especially to eliminate unnecessary radiation to patient and/or personnel? | protective curtain, filtration, collimation |
198. Which of the following has/have been identified as source(s) of radon exposure? | (indoors, in houses), (smoking cigarettes) |
199. The skin response to radiation exposure, which appears as reddening of the irradiated skin area, is known as | erythema |
200. The biologic effect on an individual depends on which of the followings? | type of tissue interaction(s), amount of interactions, biologic differences |
*1. Tabletop exposure rate during fluoro shall not exceed | 21mGya/min at 80kVp |
2. According to the NCRP the gestational dose equivalent limit for the embryo/fetus of a pregnant radiographer is | 0.5mSv |
3. A time of 1.5min is required for a particular fluoro exam, whose exposure rate is 150mGua/h. What is the approximate radiation exposure for the radiologic staff present in the fluoro room during examination | 3.75mGya |
4. Stochastic/probabilistic effects of radiation are those that | may be described as all or nothing, are late effects |
5. What percentage of public exposure to ionizing radiation is from medical resources | 50% |
6. Somatic effects of radiation refer to effects that are manifested | during the life of the exposed individual |
7. Guidelines for the use of protective shielding state that gonadal shielding should be used | If the patient has reasonable reproductive potential. When the gonads are within 5cm of the collimated field |
8. Interaction between ionization radiation and the target molecule that is most likely to occur is the | indirect effect |
9. Increasing field size, while leaving technical factors unchanged will | increase DAP |
10. Unit used to express kinetic energy released in matter is the | kerma |
11. Which acute radiation syndrome requires the largest exposure before the associated effects become apparent | CNS |
12. What is the establishes annual occupational dese equivalent limit for the extremities | 500mSv |
13. Occupational radiation monitoring is required when it is possible that the individual might receive more than | 5mSv |
14. sources of natural background radiation contributing to whole-body radiation dose include | terrestrial and internal nucleotides |
15.Irradiation of water molecules within the body and their resulting breakdown is termed as | radiolysis |
16. Diagnostic x-radiation are correctly described as | Low energy Low let |
Which of the following is/are used to count for the differences in tissue characteristics when determining effective dose to biologic material | tissue weighting factors Wt |
18. Xray interaction with matter that is responsible for the majority of scattered radiation reaching the image receptor is | Compton scatter |
19.The Exposure rate to a body 1.2m from the source of radiation is 53mGyah. which of the following distances would best decrease the exposure to 6mGya/h | 4m |
20. Types of secondary radiation barriers include | control booth, lead aprons, x-ray tube housing. |
21. Late radiation-induced somatic effect include | Thyroid cancer, cataractogenesis, genetic mutations |
22. Each time an x-ray beam scatters, its intensity at 1m from the scattering object is what fraction of its original intensity | 1/1000 |
23. The law of Bergonie and Tribondeau states that cells are more radiosensitive if they are | Highly proliferative, immature |
24. A thermo luminescent dosimetry system would use which of the following crystals | lithium fluoride |
25. Sources of secondary radiation include | leakage and scatter radiation |
26.All of the following have an effect on patient dose; except | focal spot size |
27. The photoelectric effect is more likely to occur with | absorbers having a high Z number. Positive contrast media |
28. An increase in total filtration of the xray beam will increase | beam HVL |
29. In radiation protection, the product of absorbed dose, tissue weighting factor and radiation weighting factor is used to determine | EfD |
30. which of the following id recommended for the pregnant radiographer | wear a second dosimeter under the lead apron |
31. The annual dose limit for medical imaging personnel includes radiation from | occupational exposure |
32. Which of the following anomalies is are possible if an exposure dose of 400 mGy (40 rad) were delivered to a pregnant uterus in the 3rd week of pregnancy | organ anomaly |
33. If a quantity of ionizing radiation is delivered to a body over a long period of time, the effect | will be less than if were delivered all at one time |
34. Moving the image intensifier closer to the patient during fluoroscopy | decrease patient dose. Improves image quality. Decrease SID |
35. Composed of non-dividing, differentiated cells | Neurons and neuroglia |
36. How does filtration affect the primary beam | It increases the average energy of the primary beam |
37. What is he minimum lead requirement for lead aprons, according to the NCRP | 0.50mm Pb equivalent |
38. The most radiosensitive portion of the GI tract is the | small bowel |
39. Immature cells are referred to as | undifferentiated cells. Stem cells |
40. What is the termed used to described x-ray photon interaction with matter and the transference of part of the photons energy to matter | scattering |
41. Advantages of anatomic compression during imaging include | decreased patient dose. improved contrast resolution. improved spatial resolution |
42. to be in compliance with radiation safety standards, the fluoroscopy exposure switch must | be the "dead-man" type |
43. Any wall that the useful xray beam can be directed towards is called a | primary barrier |
44. The annual dose limit for occupationally exposed individuals valid for | beta,x-, and gamma radiations |
45. the interaction between x-ray photons and matter shown in 3-1 us assicuated with | an inner shell electron and photoelectric effect |
46. Patient dose increases as fluoroscopic | FOV decreases |
47. Types of gonadal shielding include which of the following | flat contact. Shaped contact (co |
48. Unit of measure that express ionizing radiation dose to biological material | Sv |
49. LET is best defined as | method of expressing radiation quality. A measure of the rate at which radiation energy is transferred to soft tissue |
50. For Exposure to 10mGy of each of the following ionizing radiations, which would result in the greatest dose to the individual | internal source of alpha particles |
51. Skin expose to radiation exposure that appears as hair loss in known as | epilation |
52. Types of structural damage to a DNA molecule by ionizing radiation include which of the following | Single & double side rail scission, and cross linking |
53. the reduction in the intensity of an x-ray beam as it passes through material is termed | attenuation |
54. which type if dose-response relationship represents radiation-induced leukemia and genetic effects | linear, nonthreshold |
55. A dose of 250 mGy (25rad) to the fetus during the 7th or 8th week of pregnancy is likely to cause which of the following | neurologic anomalies |
56. late effects of radiation, whose incidence is done related and for which there is no threshold dose, are referred to as | stochastic/probabilistic |
57. which of the following is used to illustrate the relationship between exposure to ionizing radiation and possible resultant biologic responses | dose-response curve |
58. Classify the following tissues in order of increasing radio sensitivity | liver cells, intestinal crypt cells, muscle cells |
59. the largest amount of a diagnostic x-ray absorption is most likely to occur in which of the following tissues | Bone |
60. According to NCRP regulations, leakage radiation from the x-ray tube must not exceed | 1.0 mGya/h (10mR/h) |
61. Patient dose during fluoro is affected by the | distance between the patient and the input phosphor. amount of magnification, tissue density |
62. which of the following statements is are true with respect to radiation safety in fluoro | tabletop radiation intensity must not exceed 21mGya/min/mA. Tabletop radiation intensity must not exceed 10mGya/min. In high-level fluoro, table top intensity should be up to 200mGya/min |
63. The symbols 130/56 Ba and 138/56 Ba are examples of | isotopes |
64. Which of the following accounts for an xray beams heterogeneity | Incident electrons interacting with several layers of tungsten target atoms. Energy differences among incident electrons. Electrons moving to fill different shell vacancis |
65. Which of the following factors will affect noth the quality and the quiantity of the primary beam | Half-value layer and kV |
66. which of the following contributes mi9st to occupational exposure | Compton scatter |
67. primary radiation barriers usually require which thikness of shielding | 1/16 inch lead |
68. which of the following groups of technical factors will deliver the least patient dose | 600mA. 30 ms, 90kVp |
69. for radiographic examinations of the skull, it is generally preferred that the skull be examined in the | PA projection |
70. According to the NCRP, the annual occupational dose-equivalent limit to the thyroid, skin, and extremities is | 500mSv |
71. the average annual patient dose from medical imaging procedures in 1990 was 0.6mSc in 2017 the average annual patient dose is | 3.2mSv |
72. Which of the dose-response curve shown in figure 3-2 illustrated a linear threshold response to radiation exposure | dose response curve |
73.8The NCRP recommends an annual effective occupational dose equi9valent limit of | 50mSv |
74. Formula is a representation of the inverse square law of radiation used to determine x-ray intensity at different distances | I1/I2/D22/D21 |
75. An increase f 1.0-mm added aluminum filtration of the x-ray beam would have which of the following effects | Increase in average energy of the beam |
76. Aluminum filtration has its greatest effects on | Low-energy x-ray photons |
77. the amount of time that x-rays are being produced and directed toward a particular wall is referred to the | use factor |
78. the operation of personnel radiation monitoring device can depend on which of the following | Ionization. Luminescence. Thermoluminescence |
79. which of the following results from restriction of the xray beam | less scattered radiation production and less patient hazard |
80. How will x-ray photon intensity be affected if source-to-image distance SID is doubled | its intensity decreases four times |
81. Early symptoms of acute radiation syndrome include | Leukopenia. Nausea & vomiting |
82. figure3-3 | 82. figure3-3 |
83. Unit measurement used to express occupational exposure is | Sv |
84. which of the following refers to a regular program od evaluation that ensure the proper functioning of xray equipment, thereby protecting both radiation workers and patients | quality control |
85. Bucky slot cover is in place to protect the | fluoroscopist and technologist |
86. which type of personnel radiation monitor can provide an immediate reading | ionization chamber |
87. Which of the following terms is correctly used to describe x-ray beam quality | HVL |
88. The most effective type of shielding for anterior and lateral male gonadal protection during fluoro is | shaped contact (contour) |
89. Isotopes are atoms that have the same | atomic number but a different mass number |
90. If the ESE for a particular exposure is 1.1 mGy, what will be the intensity of the scattered beam perpendicular to and 1m from the patient | 0.001mGy |
91. the likely hood of adverse radiation effects to any radiographer whose dose is kept below the recommended guideline is | very remote |
92. Factors that contribute to the amount of scattered radiation produced include | radiation quality and field size |
93. the SSD in mobile fluroro must be | a minimum of 30cm |
94. The automatic exposure device that is located immediately under the xray table is the | ionization chamber |
95.According to the NCRP, the annual occupational whole-body dose equivalent limit is | 50mSv |
96.It is necessary to question a female patient if childbearing age regarding her | date of last menstrual period. possibility of being pregnant |
97. figure 3-4 | 97. figure 3-4 |
98. what is the effect on RBE as LET increases | as LET increases, RBE increases |
99. Which of the following would most likely result in the greatest skin dose | Short SID |
100. Which of the following radiation-induced conditions most likely to have the longest latent period | leukemia |