Comparison of endoscopic retrograde and magnetic resonance cholangiopancreatography in the surgical diagnosis of pancreatic diseases

BACKGROUND: Magnetic resonance cholangiopancreatography (MRCP) is a newly developing non-invasive examination of the biliopancreatic trees. Roles of MRCP in the diagnosis of pancreatic diseases have not been scrutinized. METHODS: Endoscopic retrograde cholangiopancreatography (ERCP) and MRCP were reviewed in 52 Japanese patients with Various pancreatic diseases and 6 patients with normal pancreas to compare their diagnostic usefulness and limitation. RESULTS: In those with normal pancreas, only the main pancreatic duct was visualized by MRCP, while both the main pancreatic and branch ducts were clearly delineated by ERCP. In 3 patients with serous cystadenoma, the tumor was not visualized by ERCP, whereas it was visible as a high-intensity mass on MRCP. Of 18 patients with a 'mucin hypersecreting' tumor of the branch type, MRCP demonstrated cystically dilated branch ducts in all, while ERCP failed to visualize the dilated ducts in 6 patients. However, the details of the cystic lesions (mural nodule, communication with the main pancreatic duct) were more exactly demonstrated by ERCP than MRCP. In 5 patients with a mucin hypersecrating tumor of the main pancreatic duct type, the dilated main pancreatic duct and the presence of mural nodules were similarly demonstrated both by ERCP and MRCP. In 12 patients with pancreatic adenocarcinoma, indirect findings were similarly demonstrated both by ERCP and MRCP, ie, stenosis (4 patients) and obstruction (8) together with dilation of the main pancreatic duct (9). In 3 patients, the center of the mass showed high intensity on MRCP, suggesting the secondary change of pancreatic carcinoma. In 8 patients with obstruction of the main pancreatic duct due to carcinoma, the distal pancreatic duct was visualized by MRCP but not by ERCP. In 9 patients who had undergone pylorus-preserving or standard pancreatoduodenectomy, follow-up MRCP was obtainable in all examined and displayed the main pancreatic duct. CONCLUSIONS: MRCP plays a complementary role in the surgical diagnosis of pancreatic disorders and is especially useful to examine the pancreatic duct after pancreatoduodenectomy.