False-negative gallbladder scintigram in acute cholecystitis.

Two cases of acute cholecystitis are described, in which the gallbladder was visualized in the hepatobiliary scintigram. While most cases of acute cholecystitis are due to cystic-duct occlusion by calculi, in a small percentage the acute gallbladder inflammation results from other pathogenic mechanisms. These cannot be excluded by gallbladder scintigram alone.