Pancreatic diseases: evaluation with MR cholangiopancreatography

Magnetic resonance cholangiopancreatography (MRCP) is a noninvasive diagnostic modality capable of producing high-quality images of the biliary tree and pancreatic duct. We evaluated the MRCP capability of depicting the normal pancreatic duct and, based on data achieved, studied the usefulness in the pathologic pancreatic duct. MRCP was performed in 42 patients without any pancreatic lesion and in 162 patients with pancreatic diseases, including congenital anomalies of biliary tree and pancreatic duct. Results were compared with endoscopic retrograde cholangiopancreatography (ERCP) in 93 patients. The visualization of the pancreatic duct and its branches and the presence or absence of dilatation, stenosis, and filling defects were recorded. All images were interpreted retrospectively and blindly by three radiologists. Among control patients, the main pancreatic duct (MPD) was depicted in the head, body, and tail of the pancreas in 41 (98%), 39 (93%), and 31 (74%), and accessory pancreatic duct and secondary branches in the head, body, and tail of the pancreas were depicted in 11 (26%), eight (19%), four (10%), and two (5%) of these patients. Compared with ERCP, MRCP overestimated the stenosis of MPD and underestimated the dilatation of the branches and filling defects in the pancreatic duct in pancreatic diseases, especially pancreatitis. However, MRCP was distinctly advantageous over ERCP in diagnosing mucin-producing tumor of the pancreas, cystic lesions, and depicting the whole, including the part distal to the obstructed site. Four of the eight cases of pancreas divisum, and 10 of the 12 cases of anomalous pancreaticobiliary duct union also were demonstrated. MRCP can accurately demonstrate the normal pancreatic duct as well as various pancreatic duct abnormalities, including congenital anomalies of the biliary tree and pancreatic duct.