Magnetic resonance imaging for diagnosing chronic pancreatitis.

Endoscopic retrograde cholangiopancreatography (ERCP) is highly sensitive for detecting chronic pancreatitis, even when mild, but it is invasive. Magnetic resonance cholangiopancreatography (MRCP), a noninvasive modality, well demonstrates dilatation, stricture, and irregularity of the main pancreatic duct as well as filling defects due to pancreatic stones and protein plugs in chronic pancreatitis. MRCP well visualizes the pancreatic ducts distal to the sites of complete obstruction and noncommunicating pseudocysts, in contrast to ERCP. MRCP is sensitive for detecting moderate to severe pancreatitis but not for mild pancreatitis. However, secretin-stimulated MRCP and technological innovations in magnetic resonance may improve diagnostic accuracy. A recently developed technique, secretin-stimulated diffusion-weighted magnetic resonance imaging (DW-MRI), noninvasively and accurately evaluates pancreatic exocrine function. In conclusion, MRCP can most likely replace ERCP for evaluation of moderate to severe chronic pancreatitis. Secretin-stimulated DW-MRI may help to detect mild or early pancreatitis.