Evaluation of gallbladder and common bile duct size and appearance by computed tomography in dogs.

The feasibility of using computed tomography (CT) to identify the common bile duct (CBD) and comparison with ultrasonography (US) results were evaluated in normal beagle dogs and dogs without hepatobiliary and pancreatic diseases. In addition, CBD diameters were obtained from CT at the level of the porta hepatis and the duodenal papilla level in dogs with underlying diseases that may cause cholestasis. US is a useful modality in the estimation of gallbladder volume because ejection fraction and CBD diameter from US were not significantly different from those of CT. The normal biliary tract was visible on CT images in 68% of the normal dog group. CBD diameter was not over 3 mm and 3.5 mm at the porta hepatis and duodenal papilla levels, respectively in normal dogs weighing less than 15 kg. Dogs suspected to have cholestasis associated with hepatobiliary or pancreatic diseases had significantly larger CBD than that in normal dogs.