Definition of age-dependent reference values for the diameter of the common bile duct and pancreatic duct on MRCP: a population-based, cross-sectional cohort study

ObjectiveChanges of the pancreaticobiliary ducts herald disease. Magnetic resonance cholangiopancreatography (MRCP) allows accurate duct visualisation. Data on reliable upper reference ranges are missing.DesignCross-sectional whole body MRI data from the population-based Study of Health in Pomerania were analysed. The width of the common bile duct (CBD) and the pancreatic duct (PD) was determined. We aimed to describe the distribution of physiological duct diameters on MRCP in a population of healthy subjects and to identify factors influencing duct size.ResultsAfter excluding pre-existing pancreaticobiliary conditions, CBD and PD diameters from 938 and 774 healthy individuals, respectively, showed a significant increase with age (pConclusionsThis is the first population-based study delineating age-adjusted upper reference limits of CBD and PD on MRCP. We showed that up to 18.2% of healthy volunteers would have needed diagnostic workup, if the conventional reference values were used. The utilisation of the adapted reference levels may help to avoid unnecessary investigations and thus to reduce healthcare expenditure and test-related adverse events.