Acute cholecystitis: the diagnostic role for current imaging tests.

Acute cholecystitis is a relatively common clinical entity characterized histopathologically by obstruction of the cystic duct due to either edema or stone or both. Thorough clinical assessment and selection of the appropriate diagnostic tests are crucial in making an early diagnosis before surgical treatment. Many diagnostic tests are available for imaging the gallbladder. Hepatobiliary imaging using technetium Tc 99m IDA is the test of choice to either exclude or confirm the diagnosis of acute cholecystitis and it carries a discriminating power greater than that of cholecystography or ultrasonography. In most patients the exclusion of the diagnosis of acute cholecystitis can be made as early as 30 minutes and the confirmation within three hours. The confirmation of acute cholecystitis by radionuclide imaging obviates the need for either cholecystography or ultrasonography.