Scintigraphic features of choledochal cyst.

The scintigraphic appearances of 12 surgically proven cases of choledochal cyst were retrospectively reviewed. In seven of 12 cases, radionuclide accumulated in the choledochal cyst (i.e., the dilated common bile duct) in less than 1 hr. In three additional cases, delayed accumulation (1-24 hr) within the cyst was seen. In two of the 12 cases, no ductal activity appeared and the diagnosis of choledochal cyst could not be made, although in one of these two cases delayed images were not obtained. Other frequent findings included delayed or nonvisualization of the gallbladder (11 of 12) and the appearance of prominent intrahepatic ducts (five of 12). We conclude that hepatobiliary scintigraphy is a noninvasive test useful in the diagnosis of choledochal cyst.