Class: Date: Rad T 290 Worksheet 2 1. Projectile electrons travel from a. anode to cathode. c. target to patient. b. cathode to anode. d. inner shell to outer shell. 2. At the target, the projectile electrons interact with a. outer shell electrons. c. atomic nuclei. b. inner shell electrons. d. Both a and b. 3. The efficiency of x-ray production is the tube current. a. indirectly proportional to c. not affected by b. directly proportional to d. strongly affected by 4. Most of the heat generated at the target is due to a. inner-shell ionization. c. nucleus bombardment. b. outer-shell excitation. d. K x-rays. 5. The production of heat at the anode is directly proportional to a. rotor speed. c. kvp. b. filament current. d. tube current. 6. The efficiency of x-ray production increases as increases. a. ma b. kvp c. time d. Both a and b. 7. Electron interactions at the inner shell of the target atoms produce radiation. a. gamma c. characteristic b. bremsstrahlung d. All of the 8. The useful characteristic x-rays from tungsten targets are x-rays. a. K-shell b. L-shell c. M-shell d. N-shell 9. Characteristic K-shell x-rays have an effective energy of kev. a. 0.6 b. 3 c. 12 d. 69 10. Most of the x-rays produced at the target are. a. bremsstrahlung c. gamma b. characteristic d. beta 11. At 55 kvp of the x-rays produced are bremsstrahlung. a. 15% b. 80% c. 100% d. none 12. Characteristic x-rays are produced by a. braking electrons. c. nuclear fragmentation. b. excitation of outer shell electrons. d. released binding energy. 13. The quantity of bremsstrahlung radiation increases proportionately with increased. a. kvp b. mas c. filtration d. rotor speed 14. An exposure taken at 100 kvp would have a continuous emission spectrum with a maximum energy of kev. a. 30 b. 69 c. 100 d. 140 15. Changes in result in directly proportional changes in the amplitude of the emission spectrum. a. ma b. time c. kvp d. Both a and b. 1
16. The discrete portion of the x-ray emission spectrum would change position with a change in. a. kvp c. voltage ripple b. target material d. Both a and b. 17. The amplitude of the emission spectrum is with a generator than/as with a three-phase generator. a. lower, single-phase c. higher, single-phase b. lower, high frequency d. the same, single-phase 18. A 15% increase in kvp is equivalent to a. increasing the mas 15%. c. Increasing the mas 1 1/2 times. b. doubling the mas. d. tripling the mas. 19. How does added filtration affect the emission spectrum? a. increased amplitude and a shift to the right b. increased amplitude and a shift to the right c. reduced amplitude and a shift to the right d. reduced amplitude and a shift to the left 20. Roentgens (or grays) is the measurement for x-ray. a. quantity b. exposure c. intensity d. All of the 21. The number of useful x-rays in the beam defines x-ray a. kvp. b. quality. c. quantity. d. mas. 22. Standard x-ray machines produce about mr/mas at 70 kvp measured at 100 cm SID. a. 2 b. 5 c. 10 d. 20 23. X-ray quantity increases in direct proportion to increases in. a. mas b. kvp c. distance d. filtration 24. If filter thickness is, then x-ray intensity is. a. reduced, reduced c. reduced, increased b. increased, reduced d. Both b and c. 25. A 10% increase in kvp has effect on x-ray intensity than/as a 10% increase in mas. a. the same c. less b. much greater d. much less 26. If a technologist changes the technique from 70 kvp @ 200 mas to 70 kvp @ 400 mas, then the x-ray intensity will and optical density will. a. double, double b. double, remain the same c. remain the same, will remain the same d. will remain the same, double 27. The inverse square law has the same effect on optical density and x-ray. a. intensity b. exposure c. quantity d. All of the 28. If the intensity of a 70 kvp exposure at 20 mas is 100 mr, what would it be at 5 mas? a. 25 mr b. 50 mr c. 200 mr d. 400 mr 29. If an exposure is 50 mr at an SID of 40 inches, what would the exposure be at an SID of 60 inches? a. 22.2 mr b. 33.3 mr c. 75 mr d. 112.5 mr 2
30. X-ray intensity is proportional to. a. distance b. kvp c. kvp 2 d. filtration 31. The penetrability of an x-ray beam is called x-ray. a. quantity b. quality c. intensity d. All of the 32. An x-ray beam that could pass through dense tissue would have high. a. penetrability b. quality c. quantity d. Both a and b. 33. A low quality beam would also have low a. penetrability. b. quantity. c. mas. d. intensity. 34. Beam quality is affected by a. mas and distance. c. kvp and filtration. b. kvp and mas. d. filtration and mas. 35. The half value layer (HVL) of an x-ray beam is a measurement of beam. a. intensity b. quality c. quantity d. All of the 36. Image contrast is affected by. a. beam quality b. kvp c. mas d. Both a and b. 37. The HVL is lowered by a decrease in. a. kvp b. mas c. distance d. Both a and c. 38. X-ray beam quality is improved by a. lowering kvp. c. increasing filtration. b. decreasing filtration. d. increasing distance. 39. The main purpose of added filtration is to reduce a. the HVL. c. beam quality. b. patient dose. d. beam penetrability. 40. Added filtration will beam quality and beam quantity. a. decrease, increase c. increase, decrease b. decrease, decrease d. increase, increase 41. A compensating filter is used to create optical density with a body part of thickness. a. uniform, non-uniform c. non-uniform, uniform b. non-uniform, non-uniform d. uniform, uniform 42. The two primary forms of x-ray interaction in the diagnostic range are a. Compton scattering and photoelectric absorption. b. Compton scattering and pair production. c. photoelectric absorption and coherent scattering. d. coherent scattering and Thompson scattering. 43. An incident x-ray interacts with an atom without ionization during. a. photoelectric absorption c. coherent scattering b. Compton scattering d. pair production 44. An outer-shell electron is ejected and the atom is ionized with a. photoelectric interactions. c. coherent scattering. b. Compton interactions. d. pair production. 3
45. Which x-ray interaction involves the ejection of the K-shell electron? a. coherent scattering c. pair production b. Compton interaction d. photoelectric absorption 46. The scattered x-ray from a Compton interaction usually retains of the energy of the incident photon. a. none b. little c. most d. all 47. Compton scatter is directed at (a) angle from the incident beam. a. 180º b. 90º c. 0º d. any 48. As kvp, the probability of photoelectric absorption. a. increases, remains the same c. decreases, decreases b. increases, decreases d. decreases, remains the same 49. There is complete absorption of the incident x-ray photon with a. photoelectric effect. c. pair production. b. Compton interaction. d. coherent scatter. 50. occurs only at the very high energies used in radiation therapy and in nuclear medicine PET imaging. a. Coherent scatter c. Photoelectric absorption b. Compton scatter d. Pair production 51. When the mass density of the absorber is, it results in Compton scatter. a. decreased, increased c. increased, decreased b. increased, increased d. decreased, decreased 52. K-shell binding energy increases with increasing. a. mass density b. kvp c. atomic number d. mas 53. Which has the greatest mass density? a. fat b. soft tissue c. bone d. air 54. Image fog in diagnostic imaging is caused by a. photoelectric absorption. c. pair production. b. Compton scatter. d. All of the 55. Differential absorption is dependent on the a. kvp of the exposure. c. mass density of the absorber. b. atomic number of the absorber. d. All of the 56. Attenuation is caused by. a. absorption c. transmission b. scattering d. Both a and b. 57. Barium is a good contrast agent because of its a. low atomic number. c. light color. b. high atomic number. d. low density. 58. The use of contrast agents increases the amount of a. differential absorption. c. photoelectric absorption. b. Compton scatter. d. All of the 59. A negative contrast agent is. a. air b. iodine c. barium d. water 4
60. X-rays transmitted without interaction contribute to a. photoelectric absorption. c. the image fog. b. the radiographic image. d. beam attenuation. 61. Compton interactions, photoelectric absorption, and transmitted x-rays all contribute to. a. image fog c. patient dose b. differential absorption d. attenuation 62. High kvp techniques reduce a. patient dose. c. image fog. b. differential absorption. d. All of the 63. If 5% of an incident beam is transmitted through a body part, then 95% of that beam was a. scattered. b. attenuated. c. absorbed. d. back-scattered. 5