Evaluation of common bile duct diameter using high resolution computed tomography.

The visibility rate and mean diameter of the common bile duct (CBD) were determined in 172 patients scanned with a routine abdominal technique on a GE CT/T 9800. Ninety-two (53%) had visible CBDs with the mean diameter measuring 5.3 mm. The visibility rate varied from 45 to 66% in healthy and ill patients, although the CBD diameters were similar (4.5 and 5.1 mm). The CBD was visualized more often in patients after cholecystectomy (87%), and the mean diameter was larger (8.2 mm). Using high resolution CT it seemed that the CBD could be demonstrated more frequently than the previously reported 30%.