Magnetic Resonance (MR) Cholangiopancreatography Demonstration of the Cystic Duct Entering the Right Hepatic Duct

BACKGROUND MR cholangiopancreatography is widely performed before laparoscopic cholecystectomy to rule out choledocholithiasis and to avoid iatrogenic injuries that may be related to the high frequency of anatomical variations of the biliary tree. Although most of these variants have already been demonstrated surgically and by endoscopic retrograde cholangiopancreatography and CT cholangiography, there are no references in which MR cholangiopancreatography has shown a cystic duct draining into the right hepatic biliary duct. CASE REPORT A 51-year-old woman with a history of recurrent abdominal pain underwent an abdominal ultrasound in an outside center, which revealed gallbladder cholelithiasis. In this patient, an MR cholangiopancreatography was performed and the laboratory data were obtained. Laboratory findings showed only a mild increase of cholestasis. MRCP did not reveal significant dilatation of intra- or extrahepatic biliary ducts, while the cystic duct showed an atypical insertion, draining directly into the right hepatic duct. CONCLUSIONS To avoid unintentional bile duct injuries, MRCP evaluation of the biliary anatomy is particularly important for pre-operative evaluation of patients undergoing laparoscopic cholecystectomy. In particular, in the case we describe, the right hepatic duct might have been mistaken for the cystic duct, with potentially severe surgical complications and clinical consequences.