Acute calculous cholecystitis with patent cystic duct.

In the diagnosis of acute cholecystitis, the interpretation of cholescintigraphy is usually not difficult. It is conceivable, however, that with unusual location of obstructing calculi atypical images could result. Three cases were studied with cholescintigraphy and one with cholecystography in which more distal locations of obstructing calculi resulted in partial visualization of the gallbladder and erroneous interpretations were possible. Nuclear medicine radiologists should, therefore, be aware that atypical gallbladder images may be the result of unexpected location of obstructing calculi. Clues for assisting in interpretation are offered.