ACCURACY OF LOCALIZING RADIOPAQUE MARKERS BY ABDOMINAL RADIOGRAPHY AND CORRELATION BETWEEN THEIR GASTRIC-EMPTYING RATE AND THAT OF A CANNEDFOOD IN DOGS

Objectives-To determine accuracy of abdominal radiography in locating radiopaque markers in the gastrointestinal tract and to assess correla tion between gastric emptying rate of radiopaque markers and that of c anned food. Animals-17 healthy dogs. Procedure-Dogs were fed thirty 1. 5-mm markers and ten 5-mm markers mixed in sufficient food to meet 25% of their daily caloric intake. They were then euthanatized by adminis tration of an overdose of barbiturate at 1, 2, 5, 8, or 12 hours after eating and the abdomen was radiographed. The stomach, small intestine , and large intestine were then separated and radiographed in isolatio n. The wet and dry weights of the stomach contents were determined. Th e apparent and actual locations of the markers and the gastric emptyin g rates of markers, wet matter, and dry matter were compared, using ra nk correlation. Results-All comparisons indicated significant (P < 0.0 25), high correlation coefficients (> 0.92). The mean difference betwe en the apparent and actual locations of the markers was < 3% for all c omparisons. The mean difference between the percentage of small marker s and large markers retained in the stomach and that of dry matter was 7.8 (SD, 6.2; range, 0 to 18)% and 11.9 (SD, 12.5; range, 0 to 44)%, respectively. Conclusions-The gastric emptying and orocolic transit ra tes of the markers were accurately predicted by abdominal radiography, The gastric emptying rate of the diet and the small markers and, to a lesser extent, the large markers was closely correlated, Clinical Rel evance-When fed with a special canned food diet, radiopaque markers ca n be used to assess the gastric emptying rate of food with sufficient accuracy for clinical purposes.