MRCP of congenital pancreaticobiliary malformation.

BACKGROUND: Congenital pancreaticobiliary malformations are sometimes associated with acute or chronic pancreatitis and biliary carcinoma. Currently, magnetic resonance cholangiopancreatography (MRCP) is one of the first choices for investigating and diagnosing pancreaticobiliary diseases noninvasively. We compared the accuracy of conventional MRCP and endoscopic retrograde cholangiopancreatography (ERCP) in making the diagnosis of congenital pancreaticobiliary malformations.

METHODS: In patients with pancreas divisum (n = 17), pancreaticobiliary maljunction (n = 12), choledochocele (n = 2), and annular pancreas (n = 1) who underwent ERCP and MRCP, the diagnostic accuracy and findings on MRCP were compared with those on ERCP.

RESULTS: Of the 32 patients with congenital pancreaticobiliary malformations diagnosed on ERCP, 23 (72%) presented the same diagnosis on MRCP. Complete pancreas divisum was diagnosed in 73% on MRCP based on the finding of a dominant dorsal pancreatic duct crossing the lower bile duct and emptying into the duodenum without communicating with the ventral pancreatic duct. Pancreaticobiliary maljunction was diagnosed in 75% on MRCP based on the finding of an anomalous union between the common bile duct and the pancreatic duct and the existence of a long common channel.

CONCLUSIONS: Conventional MRCP is a useful, noninvasive tool for diagnosing congenital pancreaticobiliary malformations; and the diagnostic accuracy can be increased with three-dimensional MRCP or dynamic MRCP with secretin stimulation.