CT features of divisional bile ducts in healthy Labrador Retrievers.

Abstract

Computed tomography (CT)is increasinglybeingusedfor the study of gallbladder and bile duct diseases. The first step in interpreting CT findings is understanding the cross-sectional anatomy of the structures involved, but there are no publishedstudies describing the CT features of the divisional bile ducts. In dogs, anatomic studies report two common patterns including three or four divisional bile ducts. The aim of this retrospective, descriptive, anatomical study was to describe the size and pattern of the visible divisional bile ducts, based on their location and extension, usingcontrast-enhanced CT in a group of Labrador Retrievers without evidence of hepatobiliary diseases. The correlation between the biliary duct number and dimensions, and the visceral fat area percentage (VFA%) was also evaluated. The right lateral divisional duct (RLD) was visualized in four of 40 dogs, the left lateral divisional duct (LLD) in nine of 40 dogs, and in 17 of 40 dogs, both were simultaneously visualized. In 10 of 40 dogs, the RLD and LLD were not highlighted. When visible, the RLD has a median diameter of 0.23cm and a median length of 0.82cm. The LLD has a median diameter of 0.23cm and a median length of 2.72cm. The median diameter of the common bile duct before and after the insertion of divisional bile ducts was 0.23 and 0.25cm, respectively. No correlation with the VFA% was found. At least one ofthedivisional bile ducts could be visualized usingcontrast-enhancedCT in the majority of sampleddogs (75%) .