Comparison of endoscopic retrograde cholangiopancreatography with MR cholangiopancreatography in patients with pancreatitis

PURPOSE: To assess the usefulness of magnetic resonance (MR) cholangiopancr eatography (MRCP) in the evaluation of disease in patients with acute or ch ronic pancreatitis. MATERIALS AND METHODS: MR imaging was performed at 1.5 T in 39 patients wit h chronic (n = 30) or acute (n = 9) pancreatitis. The patients underwent a. ,pancreas MR imaging protocol that included an MRCP sequence. Comparison wa s made with findings at endoscopic retrograde cholangiopancreatography (ERC P), performed within 30 days. Three blinded readers used a scoring system t o evaluate nine segments of the pancreatic and biliary ducts as depicted on the ERCP and MRCP images. MRCP image quality was also evaluated. RESULTS: Of 196 segments analyzed, 17 were not seen at MRCP (sensitivity, 9 1%). Of the segments visualized at MRCP, 14 were incorrectly characterized (accuracy, 92%). At MRCP, segments not detected or mischaracterized were ei ther normal, slightly dilated, or narrowed. At ERCP, 42 segments in 19 pati ents were not visualized. MRCP findings were considered useful in all those cases. MRCP image quality was not interpretable in two cases due to artifa cts. CONCLUSION: Very good correlation between ERCP and MRCP findings was demons trated. Both modalities failed to depict pathologic conditions depicted by the alternative method. MRCP may obviate ERCP, particularly in patients who cannot undergo ERCP or in whom ERCP has been unsuccessful.