Clinical significance of preoperative magnetic resonance cholangiopancreatography in the evaluation of anatomic variants of the extrahepatic biliary tract

Abstract

Objective To evaluate the feasibility and clinical significance of magnetic resonance cholangiopancreatography (MRCP) in the diagnosis of anatomic variants of the extrahepatic biliary tract. Methods The MRCP images of 535 patients who were admitted to The Second Affiliated Hospital of Suzhou University from March 2008 to March 2009 were retrospectively analyzed by two reviewers independently. The anatomic variants of the extrahepatic biliary tract were evaluated by studying the T2-weighted magnetic resonance images. Results The consistency between the two reviewers in the diagnosis of low choledochal joint, medial cystic duct insertion, aberrant hepatic duct, accessory hepatic duct and other anatomic variants was 98% , 99% , 89% , 90% and 100%, respectively (K = 0.86, 0.93, 0.81, 0.82, 1.00). The extrahepatic biliary system was clearly displayed by MRCP in 500 patients, and anatomic variants were observed in 240 patients, including low choledochal joint in 85, parallel cystic duct in 37, medial cystic duct insertion in 82, aberrant hepatic duct in nine, accessory hepatic duct in 10, choledochal cyst in three and high cystic duct in seven. A total of 259 patients underwent operation, and 168 patients had anatomic variants of the extrahepatic biliary tract. Conclusion MRCP imaging enables the accurate assessment of anatomic variants of the extrahepatic biliary system and avoids bile duct injury. Key words: Extrahepatic biliary system; Magnetic resonance cholangiopancreatography; Variation; Cholecystectomy