FINAL TQ

Question 1

1. What causes silver-halide crystals to remain crystalline and inactive?

Answer 1

No exposure to radiation

Question 2

2. When determining the amount of time to submerge film in a fixing bath, remember, the total fix time = …

Answer 2

2x clearing time

Question 3

3. “tree branches” on film is caused by…

Answer 3

Static electricity

Question 4

4. T/F: radiographs can’t be weight-bearing

Answer 4

False, most radiographs are weight-bearing

Question 5

5. a latent image is made when ____% of PSP retains energy

Answer 5

50%

Question 6

6. How many tones of gray are available in film imaging?

Answer 6

30-35

Question 7

7. How many tones of gray are available in computed radiography?

Answer 7

10,000

Question 8

8. T/F: You are not allowed to process in the same room while you are shooting x-rays?

Answer 8

True!…if the x-ray and processor are in the same room, the exposure will interfere with laser scanning

Question 9

9. Digital radiography _____ patient dose because it increases the kVp and decreases the mAs

Answer 9

reduces

Question 10

10. Does film have a higher or lower spatial resolution (line pairs per millimeter) than digital imaging?

Answer 10

Higher

Question 11

11. What is the spatial frequency of film?

Answer 11

8.0 lp/mm

Question 12

12. A film image degrades about ___% in 8 hours.

Answer 12

25%

Question 13

13. What is the ability to image 2 separate objects as being distinct?

Answer 13

Resolution

Question 14

14. What is the ability to distinguish anatomic

structures of similar subject contrast?

Answer 14

Contrast resolution

Question 15

15. What is the ability to image small objects that have high subject contrast?

Answer 15

Spatial resolution

Question 16

16. The _____ the speed of the film, the _____ the contrast

Answer 16

Faster, higher

Question 17

17. Every ____ increase in optical film density

doubles the exposure

Answer 17

0.3 (log2.0=0.3)

Question 18

18. The shoulder region of the characteristic film

curve tells us….

Answer 18

At a particular amount of time, the amount of radiation makes no difference.

Question 19

19. In regards to anatomic part thickness, if we increase the contrast (reduce the amount of gray tones), then we ______ magnitude of difference

Answer 19

Increase (there is a greater difference between the thick and thin anatomical parts on film)

Question 20

20. If we lower the radiation quality (kVp), we create _______ contrast

Answer 20

Higher

Question 21

21. T/F: Changing mAs affects the subject contrast

Answer 21

False

Question 22

22. When evaluating pediatric patients, exposure time

must be _______, due to thinner parts

Answer 22

Faster

Question 23

23. Source image distance is _____ for stationary units

Answer 23

Fixed

Question 24

24. To control optical density, you change ______.

Answer 24

mAs

Question 25

25. To control contrast, you change ______.

Answer 25

kVp

Question 26

26. To control distortion, you change _______.

Answer 26

Patient position

Question 27

27. when you have a high subject contrast, such as a chest, the safest way to create a lower image contrast is to use _____kVp and _______mAs

Answer 27

High kVp, low mAs

Question 28

28. In order to produce a visible change in optical density, mAs must be changed by at least _____%

Answer 28

30%

Question 29

29. In order to produce a visible change in optical density, kVp must be changed by at least _____%

Answer 29

4%

Question 30

30. For the most part, the principle action of radiation on humans is ________.

Answer 30

Indirect (due to radiolysis of water)

Question 31

31. Radiosensitivity increases as….

Answer 31

(all of the above) - age of tissue decreases - metabolic activity increases - cell proliferation rate increases - tissue growth rate increases

Question 32

32. According to the Law of Bergonie and Tribondeau, stem cells are radiosensitive. The 1st type of stem cells to be affected are…

Answer 32

Hematologic System cells (first system to affected is the blood, and you go into hematologic depression)

Question 33

33. …(continued from 32) the second type of cells to be affected are…

Answer 33

GI gut lining cells

Question 34

34. …(continued from 32) the last type of cells to be affected are…

Answer 34

CNS cells

Question 35

35. What part of the body is the least radiosensitive?

Answer 35

The foot!!!

Question 36

36. Because skin is nonlinear, what is its threshold dose?

Answer 36

200 rads

Question 37

37. What type of chromosomal aberrations are | considered to be the most significant in terms of latent human damage?

Answer 37

Multi-hit aberrations

Question 38

38. T/F: Gonadal dysfunction requires a high minimum dose.

Answer 38

False | gonadal damage can happen with only a 10rad exposure, a very low minimum dose

Question 39

39. The absolute risk is…

Answer 39

The number of cases of a given effect per rad per year

Question 40

40. The excess risk is…

Answer 40

The number of observed cases minus the expected cases

Question 41

41. the relative risk is…

Answer 41

The number of observed cases divided by the number | of expected cases

Question 42

42. The acute threshold of Cataract formation is….

Answer 42

2 Gy

Question 43

43. Females are ___ times more susceptible to thyroid | carcinoma

Answer 43

3 times

Question 44

44. Doubling dose is…

Answer 44

The amount of radiation needed to double the mutation | rate.

Question 45

45. In order to reduce exposure, we ____ time, _____ | distance, and _____ shielding.

Answer 45

Minimize time, maximize distance, employ shielding

Question 46

46. T/F: Grids do not improve patient or doctor safety

Answer 46

True

Question 47

47. What determines barrier thickness?

Answer 47

The highest energy level employed by the x-ray unit (changes from machine to machine)