Causes of false negative hepatobiliary scan resulting in the setting of acute cholecystitis
There are several reasons why the gallbladder, or a structure appearing to be the gallbladder, can be observed on a hepatobiliary scan in the presence of acute cholecystitis. False-negative results occur most commonly when the patient has acute acalculous cholecystitis. Several other structures, such as the bowel, a duplicated gallbladder, or another abnormality of the biliary tree, can show radiotracer activity in the region of the gallbladder even though the patient actually has acute cholecystitis. Another cause of false-negative results is perforation of the gallbladder, which subsequently reduces the pressure and relieves the obstruction, allowing the radiotracer to enter into the gallbladder region.
