Contrast radiography is the use of negative (air or gas) or positive (iodinated or barium based) contrast medium to highlight an area of interest.
Many contrast studies have been described among species. Doses and techniques are often extrapolated from dogs and cats.
Negative contrast studies typically involve the use of room air or carbon dioxide, if available. Typical negative contrast studies are esophograms, gastrograms and cystograms. In esophograms and gastrograms, negative contrast studies are usually used to evaluate wall thickness, or to look for a foreign body. Negative cystograms can be useful to evaluate bladder wall thickness and to look for bladder uroliths or hematomas.
Positive contrast studies use either barium or iodinated contrast media. The selection of which depends on the study being performed and likely pathologies based on the clinical presentation. Examples are listed below:
Esophogram - barium (unless perforation is suspected then iodinated)
Upper GI - barium (unless perforation is suspected then iodinated)
IVP (intravenous pyelgram) - iodinated
Dircet pyelography - iodinated
Cholecystogram - iodinated
Positive cystogram - iodinated
Urethrogram - iodinated
Myelogram - iodinated (iohexol ONLY)
If you are contemplating a contrast study in a marine mammal, please feel free to CONTACT US for advice. Contraindications and cautions do exist. A successful study requires prior planning and understanding of the timing and positioning of radiographs following contrast medium administration.