Normal caliber of the extrahepatic bile duct
The normal caliber of the extrahepatic bile duct is ≤7 mm. In older patients (>60 years) and in patients who have had previous cholecystectomy, the extrahepatic bile duct may measure up to 10 mm in caliber. In general, a diameter >7 mm without cholecystectomy should at least prompt correlation with serum liver function test parameters to determine if there is cholestasis.