Rad Lab

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Rad Lab
2010-12-13 20:28:33
Radiology Laboratory

rad lab
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  1. What is the purpose of intensifying screens?
    To improve safety and minimize motion
  2. Portable x-ray machines should be used with a stand. Why?
    The stand helps avoid radiation exposure
  3. what color film should be used with rare earth screens?
  4. The speed of the screen affects what?
    The radiation exposure needed
    After cleaning the cassette should be stored in a horizontal position until dry?
    Pressurized air is a good way to remove loose debris on the screen?
    Scratches, dirt, and chemical spills on the screens could result in a misdiagnosis and potentially unnecessary pain and suffering for the patient.
  8. CARE OF SCREENS:Commercial screen cleaners are available for screen cleaning
    Damage to a screen surface is permanent and cannot be repaired
  10. How should you place radiographs on the viewer?
    • Lateral: Walking off the to the left
    • VD: Walking towards you
  11. Describe two ways a large animal technique chart differs from a small animal technique chart
    • No Ma
    • No abdomen or thorax chart
  12. Describe two indications that tell you that the portable x-ray machine has actually exposed the film
    • flash of the light
    • hear the beep
  13. List one indication we use to determine if a lateral fetlock film is a true lateral view and not obliqued.
    The sesamoid bones are superimposed on each other
  14. Why do we like rare earth screens so much?
    Safer because of less radiation and they are quicker
  15. Explain how grids absorb scatter radiation yet let diagnostic radiation through.
    Grids are lead pieces going in a pattern that absorbs scatter radiation
  16. When do we want to use a grid in a radiographic study?
    when the patient is bigger than 10cm
  17. Define phosphor
    The things that glow in response to radiation
  18. Which of the following anatomical structures should be parallel to the cassette for a well positioned lateral skull film?
    The nasal septum
  19. In a lateral pelvic film which leg gets pulled cranially?
    The bottom leg
  20. Which bone is superimposed over the center of the distal femur on a well positioned Cr-Ca femur film?
    The patella
  21. List the four standard views we shoot of an equine tarsus.
    Dp, lateral, medial oblique, lateral oblique
  22. List the five criteria used to determine correct positioning on an OFA style pelvis film.
    • Patella between femur condyles
    • nothing is obliqued/everything is straight
    • Femur is in the middle of the cassette/beam
    • AOI-Sacrum to stifles
    • restrained properly
  23. Describe the location for the lables for each of the 3 equine carpal views
    • Lateral: cranial
    • DPO: Lateral
    • Felx: Cranial
  24. Why do we need to use the bisecting angle technique when performing dental radiography?
    so we get the whole tooth and the root in one radiograph
  25. Describe two ways to restrain birds for whole body films
    tape, lead bags
  26. How do we position the little bump on the dental film?
    Rostral and toward the tube
  27. When might a frog-leg position be preferable to the standard OFA type positioning for a VD pelvic radiograph
    Broke pelvis
  28. if you are exposing a lateral view of the right femur which side of the patient is the downside?
  29. Why is positioning so crucial with skull radiographs
    Because of the different densities
  30. What does collimation have to do with spinal film?
    Helps prevent scatter radiation since the spine is small and doesnt need to take up the entire film
  31. What is the name of the DJD that affects some equine distal medial hock joints
    Bone spavin
  32. what is the anatomical name for the point of the hock
  33. What is the relationship between the density of an object and its appearance on the film
    More density the whiter it is
  34. Why do we care about bubbles on the film
    creates artifacts on the film
  35. what color is exposed correctly processed film?
  36. What color is unexposed correctly processed film
  37. List two reasons why it is important to stir the developer before placing the thermometer in the tank
    Mix the solution and temperature
  38. Why was the shape of the upright bolts different for the different bolt positions
  39. What effect would this have on the shape of an organ or bone in a patient
    Blurr and even become unrecognizable
  40. What can we do to avoid scatter radiation
    Center the AOI and grid
  41. Why are the bolts visible outside the area of collimation?
    Scatter radiation
  42. Why do we care about the effect of scatter radiation
    unsafe and poor image detail
  43. Define radiographic density
    degree of blackness or darkness on a radiograph
  44. Define grid factor
    The amount the exposure needs to be increased to compensate for the grids absorbtion of a portion of primary beam
  45. What would film look like if it should be a tabletop film but you use the bucky
    Light image
  46. What would a film look like if you were suppose to use the bucky and instead used the tabletop
  47. what is in the intensifying screens that allow them to flouresce
    rare earth
  48. What color of light did the screens produce
    • tungstate= blue
    • rare earth= green
  49. Someone ordered the wrong film (blue instead of green). What would look different on a developed film.
    Lighter in color
  50. When looking at your developed film, how can you tell if you achieved a true lateral position
    The sesamoide bones are super imposed
  51. Why not expose the film as a ML view rather than a LM?
    You have to get under the horse for that
  52. ho can you protect yourself from radiation exposure during a fetlock study
    Lead, keep out of the beam face forward not backward
  53. List two disease conditions that could cause your DVM to ask you to x-ray an equine fetlock
    • OCD
    • Synovitis
  54. List a handling/restraint trick used to encourage horses to bear full weight on the leg you are radiographic
    Lift up opposite leg
  55. Why might your DVM request an x-ray series of the carpus
  56. List two reasons why we should use the tripod stand when using the portable x-ray machine
    avoid radiation exposure, in case the horse kicks it doesn't get dropped as well
  57. What was the most difficult aspect of patient positioning for the CrCa view of the femur?
    Straightening the leg enough to lay flat against the cassette
  58. List the anatomic structures that are included in a good femur film
    hip joint full femur stifle joint
  59. If you are positioning a lateral view of the left femur what side of the patient is the downside
  60. where do we measure the femur for the CrCa view
    Middle where theres more muscle
  61. On a lateral pelvic film what can we do to avoid pelvic rotation and still keep the femurs parallel to each other
    wedge foam between the legs
  62. what is the Penn-hip method of screening for hip dysplasia
    • standard extended
    • compression with neutral position
    • distraction with some neutral position
  63. List a urinary tract injury that often occurs with a pubic bone fracture
    ruptured urethra
  64. Which radiographic procedure could be used to definitively diagnose this condition
  65. How do we estimate the bisecting angle
    Angle the film the teeth and the middle to find the angle
  66. list two small animal dental conditions diagnosed using dental radiography
    • gingivitis
    • periodentis
  67. Why is sedation o anesthesia necessary for good quality head and neck films
    controlled patient is vital for precise and symmetrical film
  68. Why is positioning so crucial in skull radiographs
    to avoid oblique films
  69. After exposure and developing how can you tell if the VD cervical spinal film is obliqued
    you dont have the wings of the atlas symmectrical
  70. List the POM and beam center for a CXR
    • POM=Caudal scapula
    • BC= caudal boarder of the scapula
  71. How can we tell from looking at a CXR film that is is well-positioned
    The ribs are superimposed and or parrallel
  72. What does the guideline the thorax is inside the rib cage have to do with take a CXR
    We need all of the ribs to get all of the thorax
  73. Why do we shoot a CXR at full inspiration
    the diaphragm is pushed back away from the heart so we see the lungs at max copacity
  74. How can we tell whether the film is a full inspiration
    there is space between the heart and the diaphragm
  75. What are the cranial and caudal anatomical limits for an AXR
    • Cranial= diaphragm
    • Caudal= femoral head
  76. List the POM and beam center for an AXR (difference between cats and dogs)
    • POM: Dogs=caudal aspect of the 13th rib
    • Cats=Same
    • BC: Dogs= 13th rib
    • cats= two fingers behind the 13th rib
  77. Why is it important to pull the hind limbs caudally when positioning for a lateral AXR
    Get the legs out of the way
  78. Why is it not important to stretch the hind limbs caudally with a VD or DV AXR
    its not in the view
  79. Do we expose AXR on expiration or inspiration? Why
    Expiration. diaphragms pushed up and out of the way
  80. What are the 2 standard views for an AXR? why?
    • Right lateral
    • VD

    you might see something that looks like its deep in the abdomen when its really in the skin
  81. What would an abdomen full of blood (or urine) look like on an AXR why?
    No detail no content
  82. Why is it important to fill the frog area with Play-do
    Prevents the appearance of an air artifact superimposed over the AOI
  83. List and describe two ways to get a DPO view of the navicular bone
    On a cassette in a cassette tunnel on a block with a specially designed grooves that hold the hoof at an angle