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effective doses? -nm exams -barium enema -Upper Gi

effective doses? -nm exams -barium enema -Upper Gi. NM exams- 5 mSv or 500 mRem Barium Enema- 3-7 mSv or 300-700 mRem Upper GI- 2-4 mSv or 200-400 mRem. what is the increase risk of cancer in kids given radiation?. 6/10,000 per rem (0.06% per rem) (6% per Gy).

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effective doses? -nm exams -barium enema -Upper Gi

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  1. effective doses?-nm exams-barium enema-Upper Gi

  2. NM exams- 5 mSv or 500 mRem • Barium Enema- 3-7 mSv or 300-700 mRem • Upper GI- 2-4 mSv or 200-400 mRem

  3. what is the increase risk of cancer in kids given radiation?

  4. 6/10,000 per rem • (0.06% per rem) • (6% per Gy)

  5. what is the increase risk of cancer in adults given radiation?

  6. 4/10,000 per rem • (0.04% per rem) • (4% per SV)

  7. pet sensitivity increases with _____?

  8. Increased septa thickness

  9. pet resolution increases with _____?

  10. Detector efficiency squared

  11. slice selection gradient in mr?

  12. -Gradient encoding • -Z-axis during RF pulse

  13. whole body specific absorption ratio (sar) for Mr?

  14. -RF power absorbed per unit of mass of an object • -Potential for heating of the patients tissue due to the application of the RF energy necessary to produce MR signal • -Decreases 0.4 W/Kg • -Decreases 3.2 W/Kg for head

  15. What is chemical shift artifact?

  16. -Both answers were similar on the test so read carefully. • -Slight difference in resonance frequency of protons in water and fat. • -Fat shifts in the frequency encoding direction.

  17. wavelength of conventional radiograph?

  18. 0.5 - 1 nm • -on the test, this was not an answer choice but it gave • 0.1- 5 nm?

  19. what is effective dose?

  20. -Combines all organ doses and their relative radiosensitivity. • -Best indicator of patient risk in NM. • -AKA dose equivalent • -Proportional to current (MA) & Scan time.

  21. flat panel detectors?

  22. Are more efficient x-ray absorbers and require less radiation to achieve the same image quality.

  23. How can you decrease geometric unsharpness?

  24. Decrease SID • Decrease source to image distance

  25. natural background radiation exposure?

  26. 3 mSv/ year • or • 300 mRem/ year

  27. leakage radiation

  28. Decreases 1 mGy/hr @ 1 meter

  29. slice location selected by?

  30. RF gradient

  31. mr aliasing?

  32. High wraps to low frequency • Wrap around to lower frequency

  33. how is an extrinsic flood performed?

  34. Co-57 Sheet with collimator

  35. how is intrinsic flood performed

  36. TC-99 point source without collimator

  37. LD 50/60

  38. 450 Rad • 250-300 Rad

  39. What makes pet better than spect?

  40. Annihilation coincidence

  41. what do flat panel detectors use?

  42. CSI scintillator

  43. mc anode/ filter in mammo?

  44. Mo- Mo • Mo- Rh • Tungsten • Silver

  45. the us beam can be

  46. Reflected, refracted, scattered & absorbed

  47. Photoelectric interactions are proportional to

  48. Z^3/ E^3

  49. HVL soft tissues?

  50. 2.5- 3 cm • 25- 30 mm

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