SONOGRAPHIC OBSERVATIONS OF THE GASTRODUODENAL JUNCTION OF DOGS

Objectives-To determine the sonographic dimensions and an imaging prot ocol for the pyloric region of the normal canine stomach, and whether sonography could be used to demonstrate antroduodenal motility. Animal s-20 clinically normal, mixed-breed dogs (mean +/- SD, 15.1 +/- 7.1 kg ).Procedure-in vitro sonographic observations of the gastroduodenal ju nction were made after each had been mounted on an acrylic rack placed in an organ bath. The in vivo studies were performed in anesthetized dogs. Results-The wall of the pyloric antrum was 4 to 5 mm thick, that of the pylorus was 3 to 4 mm thick, and that of the cranial part of t he duodenum was 2 to 3 mm thick. The pyloric canal had a length of 16 to 17 mm and overall in vivo diameter of 22 mm, and the muscular part of its wall was 2 to 3 mm thick. In vivo sonographic images were best made with the dog in dorsal recumbency, tilted 30 degrees to the right -the feasibility study clearly demonstrated the form and function of a ntroduodenal motility including gastric and duodenal peristalsis, open ing and closing of the pyloric canal, and duodenogastric reflux of flu id and gas. Conclusions and Clinical Relevance-The use of a routine im aging protocol, accompanied by mensuration of the gastroduodenal junct ion, will permit an opinion to be given as to whether the structure an d function of the region are normal or whether pathologic change exist s.