MR Cholangiopancreatography (MRCP)

Non-invasive MRI of the bile ducts and pancreatic duct system. Radiation-free alternative to ERCP for diagnosing gallstones, strictures, and ductal abnormalities.

MR cholangiopancreatography (MRCP) uses heavily T2-weighted sequences to visualise the biliary tree and pancreatic duct as bright fluid-filled structures against a dark background, without the need for contrast injection or endoscopic access. The technique provides a non-invasive roadmap of the biliary anatomy from the intrahepatic ducts through the common bile duct to the ampulla, plus the main and accessory pancreatic ducts. MRCP is the standard non-invasive investigation for suspected choledocholithiasis (common bile duct stones), biliary strictures, primary sclerosing cholangitis, pancreatic duct anomalies (pancreas divisum, intraductal papillary mucinous neoplasms), and post-cholecystectomy biliary complications. It has largely replaced diagnostic ERCP, which carries procedural risks including pancreatitis and perforation. The examination requires fasting (typically 4-6 hours) to ensure gallbladder distension and reduce bowel fluid that might mimic ductal structures. The radiologist provides coronal and axial source images plus thick-slab cholangiographic projections that simulate the traditional ERCP appearance.