RT 110 quiz 4 (midterm stuff)

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RT 110 quiz 4 (midterm stuff)
2011-10-21 16:44:28
RT 110 quiz midterm stuff

RT 110 quiz 4 (midterm stuff)
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  1. Personnel monitoring is required when a worker may receive __% or more of the annual MPD
  2. Personnel monitoring is done when __% is expected
  3. Where is the placement for personnel monitoring?
    • Collar level
    • Outside the apron if used
    • *second may be used for pregnancy
    • *extremity monitors also
  4. What are the types of devices used for personnel monitoring?
    • Film badges- 10 mrem to 500 rem
    • OSL; MC
    • TLD
    • Pocket ionization chambers
  5. What are the ranges for a film badge?
    10 mrem to 500 rem
  6. What is the device that is used today and how does it work?
    • OSl; MC
    • Aluminum oxide which is read by a laser that is typically worn for 2 months
    • 1 mrem and sensitive to 5keV to 40 MeV of energy
  7. What personnel monitoring device cannot be reread?
    TLD. It is reasonably sensitive and made out of Lithium floride
  8. Which personnel monitoring device is good for immediate feedback?
    • Pocket ionization chambers
    • But they are not very reliable because they are very sensitive and will get a reading even when dropped.
  9. For immobilization, what kind of motion is lack of control: voluntary or involuntary?
    • Voluntary motion
    • Immobilization devices work with this group
  10. What are the beam limiting devices that limit the amount of tissue the beam is exposing?
    • Diaphragms
    • Cones
    • Collimators
  11. What is the name of an automatic collimator that collimates to the filed size when put in the bucky tray?
    Positive beam limitation (PBL)
  12. Filtration (Not a question, just notes)
    • Inherent just added filtration
    • Aluminum added to meet requirements
    • Mobiles/portables and fluoro units are required to have at least 2.5 mm Al
    • The filter absorbs the low energy wavelengths and get rid of the ones with no diagnostic value. Only the high wavelengths penetrate the filter and go through
  13. The amount of aluminum required to reduce the beam intensity to half its original value is called
    Half value layer (HVL)
  14. As kVp increases, the penetrability of the beam _____ (increases or decreases?)
  15. The amount of Al necessary to half the beam intensity will have to be ________ (increased or decreased?)
  16. Gonads need to be shielded when they are within ___ cm of the beam
    5 cm (unless shielding will obscure anatomy)
  17. Gonadal shielding is required to have at least __ mm Pb (lead)
    0.5 mm Pb
  18. Is is always require to shield all the time?
  19. What are some types of gonadal shielding?
    • flat contact
    • shadow
    • shaped contact
    • clear lead
  20. What is used for shielding of the breast during a scoliosis screening? Flat contact, shadow, shaped contact or clear lead?
    Clear lead
  21. What position is used for an x-ray of the breast during a scoliosis screening? PA or AP?
  22. Compensating filters (notes only)
    • Trough or bilateral wedge- for chest images
    • Wedge filter
    • Specialized metal filters- copper
  23. Which one is correct?
    High kVp high mAs
    High kVp low mAs
    Low kVp low mAs
    High kVp low mAs
  24. What insures that the processor is maintained to a standard level of acceptance?
    QC- quality control
  25. Rare earth screens are generally faster or slower?
    Faster. Due to their higher atomic number which results in higher absorption of photons. More light is produced per photon meaning less photons have to be used for a good film.
  26. What prevents scattered radiation from reaching the film?
  27. Grids increase or decrease patient dose?
  28. Film quality for grids are dramatically improved or dramatically worsened?
    Dramatically improved
  29. SID must be a minimum of __ inches
    12 inches
  30. The longer the SID the ____ the patient dose (lower or higher?)
  31. Collimator and light field is +/- __% of the SID
  32. What are 2 types of digital imaging?
    CR and DR
  33. Primary shielding is __ mm Pb or __ inches
    • 2.5 mm PB
    • 1/16 inches
  34. Secondary shielding is __ mm Pb or __ inches
    • 1.25 mm Pb
    • 1/32 inches
  35. Gonadal shielding is __ mm Pb
    0.5 mm Pb
  36. Protective apparel for shielding is __ mm Pb
    0.25 mm Pb
  37. Cellular amplification is?
    When there is damage to the cell and when it divides, it carrys on that defect to the next cells that are produced.
  38. Increase kVp, ____ beam energy, ___ frequency of photons, ___wavelength, ___ absorption, ___ patient dose, ___ density, ___ scatter, ___ contrast. (increase or decrease?)
    • increase beam energy
    • increase frequency of photons
    • decrease wavelength
    • decrease absorption
    • decrease patient dose
    • increase density
    • increase scatter
    • decrease contrast
  39. Decrease kVp, ____ beam energy, ___ frequency of photons, ___wavelength, ___ absorption, ___ patient dose, ___ density, ___ scatter, ___ contrast. (increase or decrease?)
    • decrease beam energy
    • decrease frequency of photons
    • increase wavelength
    • increase absorption
    • increase patient dose
    • decrease density
    • decrease scatter
    • increase contrast