Type I biliary atresia without extrahepatic biliary cyst.

Currently, magnetic resonance cholangiography (MRC) is used for the differentiation of biliary atresia (BA) from other causes of infantile cholestasis. The authors present a case of type I BA without an extrahepatic biliary cyst in a 2-month-old girl. MRC clearly visualized the patency of the gallbladder, cystic duct, and hepatic ducts with disappearance of the common bile duct. Intraoperative cholangiography demonstrated a cloudy appearance of the intrahepatic bile ducts, confirming the diagnosis of type I BA. We believe that this is the first reported case of type I BA without an extrahepatic biliary cyst diagnosed by MRC.