click below
click below
Normal Size Small Size show me how
X-Ray Test 1
X-Ray Tube
Question | Answer |
---|---|
1. The most widely used support structure for the x-ray tube is the... | ceiling support system |
2. The external structure of the x-ray tube includes the support structure, the protective housing, and the ... | glass envelope |
3. The negative side of the x-ray tube holds the ... | filament |
4. What is the most common cause of tube failure? | tungsten vaporization |
5. The target of the rotating anode is usually coated with a ________ alloy. | tungsten |
6. The ______ is the source of radiation in the x-ray tube. | focal spot |
7. High capacity tube rotors revolve at ______. | 10,000 rpm |
8. The x-ray intensity is lower on the anode side of the tube because of the ... | heel effect |
9. Tube failure can occur from ... | long exposure times |
10. A dual focus tube has two | filaments |
11. Each tube has its own tube rating chart to show... | maximum exposure time |
12. The _______ is/are outside the glass envelope. | stators |
13. The heel effect is caused by the ... | anode angle |
14. The effective focal spot size is _____ the actual focal spot size. | smaller than |
15. Localized pitting or cracking on the anode can occur from ... | a single excessive exposure |
16. Most of the heat generated at the target is due to ... | outer-shell excitation |
17. The production of heat at the anode is directly proportional to ... | tube current |
18. Approximately _____% of the kinetic energy of the projectile electrons is converted to x-rays at the target. | 1% |
19. Electron interations at the inner shell of the target atoms produce _____ radiation. | characteristic |
20. The useful characteristic x-rays from tungsten targets are _____(shell) x-rays. | K-shell |
21. Most of the x-rays produced at the target are _____. | bremsstrahlung |
22. At 55 kVp ____% of the x-rays produced are bremsstrahlung. | 100% |
23. Bremsstrahlung x-rays are produced by _____ at the target. | slowing electrons |
24. Characteristic x-rays are produced by ... | released binding energy |
25. An exposure taken at 100 kVp would have a continuous emission spectrum with a maximum energy of _____ keV. | 100 |
26. An increase in mAs would (increase or not affect) the (amplitude or position) of the emission spectrum. | increase, amplitude |
27. The discrete portion of the x-ray emission spectrum would change position with a change in (kVp, target material, or voltage ripple). | target material |
28. How does added filtration affect the emission spectrum? (increased or reduced amplitude) and (shift to right or left) | reduced, right |
29. The number of useful x-rays in the beam defines x-ray... (kVp, quality, quantity or mAs) | quantity |
30. Standard x-ray machines produce about ___ mR/mAs at 70 kVp measured at 100 cm SID. | 5 mR/mAs |
31. If filter thickness is _____, then x-ray intensity is _____. (increased or reduced) and (increased or reduced). | There are two answers increased, reduced and reduced, increased (filtration is proportional to spectrum, speed inversely to dose). |
32. If x-ray quantity is doubled, the optical density on the finished radiograph will be ... (reduced by half, just slightly increased or increased by a factor of two) | increased by a factor of two |
33. 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 ____. (double or remain the same) both lines | double, double |
34. An increase of 15% in kVp is equivalent to increase mAs ____%. | 100 |
35. If an exposure is 50 mR at an SID of 40 inches, what would the exposure be at an SID of 60 inches? | 22.2mR (inverse square law) |
36. An x-ray beam that could pass through dense tissue would have high ____. (penetrability, quality or quantity). | Both penetrability and quality |
37. A low quality beam would also have low ... (penetrability, quantity, mAs or intensity). | penetrability |
38. Image contrast is affected by ... (beam quality, kVp or mAs). | Both beam quality and kVp |
39. Added filtration will ____ beam quality and ____ beam quantity. (decrease or increase) both lines. | increase, decrease |
40. The scattered x-ray from a Compton interaction usually retains ____ of the energy of the incident photon. (none, little, most, all) | most |
41. Compton scatter is directed at ____ degrees angle from the incident beam. (0, 180, 90, any) | any degrees |
42. Only at energies above 10MeV can ____ take place. (photodisintegration, pair production, Compton Scatter or photoelectric absorption) | photodisintergration |
43. When the mass density of the absorber is ___, it results in ____ Compton scatter. (increased or decrease) both lines | increased, increased |
44. Because of differential absorption, about ___% of the incident beam from the x-ray tube contributes to the finished image. | 0.5% |
45. Attenuation is caused by ___. (absorption, scattering or transmission) | absorption and scattering |
46. Barium is a good contrast agent because of its... | high atomic number |
47. The use of contrast agents increases the amount of (differential absorption, Compton scatter or photoelectric absorption) | All of them |
48. A negative contrast agent is ___. (air, iodine, barium or water) | air |
49. X-rays transmitted without interaction contribute to ... (photoelectric absorption, the radiographic image, image fog or beam attenuation) | the radiographic image |
50. If 5% of an incident beam is transmitted through a body part, then 95% of that beam was ... (scattered, attenuated, absorbed or back-scattered) | attenuated |