CT of choledochal cyst.

Ten preoperative cases of choledochal cyst and five patients who had had complications after surgical treatment for their choledochal cysts were studied to evaluate the accuracy of computed tomography (CT) in the diagnosis of this malformation and its complications. Choledochal cysts were accurately diagnosed by CT in seven and suggested in three of the 10 preoperative patients. CT provided the correct diagnosis in all six patients with intrahepatic involvement. The CT pattern of congenital dilatation of the intrahepatic ducts was strikingly different from that of an acquired obstructive one. CT was also effective in the postoperative follow-up patients. In addition, within this group of 15 patients, three choledochal cyst cancers were detected.