Non-invasive imaging techniques such as ultrasound (US) or computed tomography (CT) are widely used for the diagnosis and monitoring of many pancreatic and biliary tract diseases. However, these techniques have limitations, such as the low sensitivity of ultrasound for detecting common duct calculi, which means that the diagnosis of several common conditions including tumours (benign and malignant), calculi, sclerosing cholangitis and chronic pancreatitis may still require invasive procedures such as endoscopic retrograde cholangiopancreatography (ERCP) or percutaneous transhepatic cholangiography (PTC).

These invasive techniques also have disadvantages—for example, ERCP requires direct cannulation of the common bile or pancreatic duct, sedation, the use of ionising radiation and a team of trained, experienced personnel. Complications include haemorrhage, sepsis, pancreatitis, bile leakage, as well as a recognised mortality.1 ERCP may not be technically possible and this, along with the complication rate, has been related to operator experience.2 In clinical practice these complications are usually offset by the diagnostic information obtained and the ability to proceed immediately to therapeutic intervention when required.

Magnetic resonance cholangiopancreatography (MRCP) is a relatively new technique for non-invasive imaging of the biliary and pancreatic duct systems. Early trials suggest that it may have a useful role in clinical practice.