Contrast Radiograph

  1. Define contrast radiograph.
    radiographs made after contrast material is placed into or around the structrue to be visualized.
  2. Why do we do contrast radiographs?
    confirm or disprove a suspected diagnosis
  3. What are the three things contrast radiographs can better identify?
    • size
    • shape
    • position
  4. What can contrast radiograph tell about mucosal surfaces?
    condition of the inner lining of hollow organs (thickness and regularity, are there ulcers?)
  5. What are survey radiographs?
    plain radiographs with no contrast material
  6. What must be done preferably immediately before a contrast radiograph?
    a survey radiograph
  7. Why must a survey radiograph must be done immediately before a contrast radiograph?
    • to make sure the contrast study is necessary
    • check patient prep
    • for comparison to the contrast film
    • make sure the exposure factors are proper
  8. Why is patient prep very important for a contrast radiograph?
    determines whether the contrast study is of diagnostic quality.
  9. What are the different things we need to do for patient prep when getting ready for a contrast radiograph?
    • remove collars, splints, bandages if possible
    • allow patient to urinate and defecate
    • clean and dry
    • clean out GI tract
  10. What can happen to the contrast radiograph is a patient is wet, muddy, covered in blood or other debris?
    • there will be loss of detail and will have artifacts
    • any fluid on the animal will show up as tissue density on the radiograph
  11. What is the purpose for cleaning out the GI tract before a contrast radiograph?
    remove stomach and intestinal contents to give us better detail
  12. What types of contrast radiographs will we need to clean out the GI tract for?
    • GI
    • urinary tract
    • other abdominal studies
  13. What are the three different ways to clean out the GI tract?
    • fasting
    • laxatives, mild cathartics
    • enemas
  14. How long should we fast our patients for a contrast radiograph?  How long should we hold off water from the patient?  What do we do if the patient is needing fluids and we can't take water away?
    • 12 hours minimum
    • at least 3 hours
    • IV fluids
  15. Define laxatives.
    substances that stimulate evacuation or emptying of the GI tract
  16. When are laxatives usually given before a contrast radiograph?
    given 12 and 24 hours before
  17. What is a mild cathartics?
  18. What is an example of a laxative?  How much should be given for a small dog/cat, medium dog, large dog?
    • milk of magnesia
    • small dog/cat:  1.0 ml/lb
    • medium dog:  0.6 ml/lb
    • large dog:  0.3  ml/lb
  19. What types of enemas can we use?
    • mild soapy water
    • saline
    • Fleet
  20. Who should we avoid using Fleet in and why?
    • cats and small dogs
    • causes an electrolyte imbalance
  21. What are contrast agents used for?
    used to opacify or outline structures
  22. What are contrast agents also called?
    • contrast material
    • contrast medium
  23. Define contrast agent.
    substance placed into the body to outline a structure not normally seen well on survey radiographs
  24. What are the general categories of contrast agents?
    • positive
    • negative
  25. What does a positive contrast agent look like on a contrast radiograph?
  26. What are the two different positive contrast agents?
    • liquid (solution or suspension)
    • barium
    • iodine
  27. Is barium water soluble?
  28. What is barium?
    suspension of micropulverized powder in water
  29. What color is barium?
  30. What are two ways to buy barium?
    • powder that we mix ourselves
    • premixed
  31. How can barium be given?
    orally or rectally into GI tract
  32. Which is more irritating, barium or iodine?
  33. What will happen if barium leaks into tissue through  a rupture?
    it will cause a granulomatous inflammatory reaction
  34. What costs more, iodine or barium?
  35. What is Estophotrast?
  36. Describe Estophotrast.
    • commerically prepared
    • thick paste for esophagraphy
    • hard to swallow
    • coats mucosa well
  37. Are iodinated compounds water soluble?
  38. What do iodinated compounds look like?
    clear liquid solution
  39. What two forms do iodinated compounds come in?
    • oral
    • injectable
  40. Iodinated compounds are hypertonic.  What does that mean?
    • tends to dehydrate
    • diuresis or draws water into the bowels
  41. What kind of patients should we avoid iodine in?
    dehydrated or debilitated patients
  42. Does iodine pass through the GI system faster than barium?  Why or why not?
    • yes
    • thinner, more water than barium
  43. What kind we give patients when using iodine?  Why would we do this?
    • IV fluids
    • keeps them from getting dehydrated
  44. When is iodine preferred over barium?
    when there is a suspected rupture in the GI tract or bladder
  45. What are two examples of iodine?
    • Gastrografin (for gastro)
    • Renografin (for urinary)
  46. What is Gastrografin made of?
    meglumine and Na diatrizoate
  47. What is a contraindication for Gastrografin?
    not recommended for cats
  48. What is Gastrografin used for?
    GI studies
  49. Does Gastrografin coat the  GI mucosa wall well?
  50. What is Renografin used for?
    urinary tract studies
  51. What is IVP?
  52. What are negative contrast agents?
  53. What do negative contrast agents look like on a radiograph?
  54. What different gases are negative contrast agents?
    • room air
    • carbon monoxide
    • nitrous oxide
    • oxygen
  55. What are negative contrast agents?
  56. What are some ways we can give a negative contrast agent?
    • can give carbonated beverage by stomach tube (CO2 is released into the stomach)
    • pill available to release gas into the stomach (example - Alka - Seltzer)
  57. What is an air embolism and when can this happen?
    • if blood vessels are ruptured, a gas bubble can get into the blood circulation
    • can happen with a negative contrast agent
  58. Are air embolisms common when using a negative contrast agent?
  59. How long does it take for room air, CO2 or N2O to dissolve in the blood when an air embolism occurs?
    • room air:  up to 2 weeks
    • CO2 & N20:  in a few hours
  60. Define double contrast.
    use of both positive and negative contrast material in the same structure at the same time
  61. How do we position a patient for a contrast radiograph?
    place the area of interest closest to the film for the clearest image
  62. When positioning a patient for a thoracic contrast radiograph what should we include?
    • first pair of ribs (thoracic inlet)
    • through the diaphragm
  63. When positioning a patient for an abdominal contrast radiograph what should we include?
    • diaphragm through hip joints
    • hold tail out of the way
  64. What position is preferred for an abdominal contrast radiograph?
    right lateral
  65. Why is a right lateral preferred for a contrast radiograph?
    • allows stomach gas to movve into the fundus
    • outlines stomach and liver better than a left lateral
  66. Why is a left lateral not preferred for a contrast radiograph?
    • gas rises into pyloric area and causes smaller, thicker gas bubble
    • does not outline the stomach and liver as well as a right lateral
  67. Other than lateral view, what kind of position should we use for an abdominal contrast radiograph?
    VD - frog leg view preferred over extended view
  68. Why is the frog leg view preferred over the extended view for a contrast radiograph?
    • the patient is more relaxed
    • the abdomen is not as compressed, organs are spread out a little
  69. How do we label a contrast radiograph?
    the usual information for a radiograph plus sequential studies (upper GI series, IVP, etc), mark time clearly on each film
  70. Should we use anesthesia for a esophagography?  Why or why not?
    no, because the patient needs to be able to swallow
  71. Can we use anesthesia for a myelography?
    yes, because it is a contrast study around the spinal cord
  72. What are some reasons why we would not perform a contrast radiograph on patient?
    • stress
    • dehydration
    • anesthetic risk
    • possibility of perforations
    • hypersensitivity to contrast agent
Card Set
Contrast Radiograph
Clinical Practice ll