a common anatomic variation is to have an extrahepatic junction of the right/left hepatic ducts.(20% of people)
it is useful to make note of this in the report, particularly if it is a very distal junction. during cholecystectomy surgery, the common duct is cannulated to image for duct calculi which may be missed. also to avoid mistaking the rhd for the cystic duct.
- a less common, but important variation, is for the right hepatic duct to join the cystic duct rather than merge with the lhd.