MR cholangiopancreatography of bile and pancreatic duct abnormalities withemphasis on the single-shot fast spin-echo technique

Magnetic resonance cholangiopancreatography (MRCP) is used for noninvasive work-up of patients with pancreaticobiliary disease. MRCP is comparable wit h invasive endoscopic retrograde cholangiopancreatography (ERCP) for diagno sis of extrahepatic bile duct abnormalities. In patients with choledocholit hiasis, calculi appear as dark filling defects within the high-signal-inten sity fluid at MRCP. Benign strictures due to sclerosing cholangitis are mul tifocal and alternate with slight dilatation or normal-caliber bile ducts, producing a beaded appearance. Dilatation of both the pancreatic and bile d ucts at MRCP is highly suggestive of a pancreatic head malignancy. Sidebran ch ectasia is the most prominent and specific feature of chronic pancreatit is. MRCP is more sensitive than ERCP in detection of pancreatic pseudocysts because less than 50% of pseudocysts fill with contrast material. Because the mucin secreted by biliary cystadenomas and cystadenocarcinomas causes f illing defects and partial obstruction of contrast material at ERCP, MRCP i s potentially more accurate in demonstrating the extent of these tumors. In patients with biliary-enteric anastomoses, MRCP is the imaging modality of choice for the work-up of suspected pancreaticobiliary disease. A potentia l use of MRCP is the demonstration of aberrant bile duct anatomy before cho lecystectomy. MRCP is also accurate in detection of pancreas divisum.