Scintigraphic findings in acute gangrenous cholecystitis.

Nine patients who had surgically proven acute gangrenous cholecystitis and Tc-99m DISIDA scintigrams were reviewed retrospectively. Three types of scintigraphic findings were presented: 1) nonvisualization of the gallbladder, three cases; 2) nonvisualization of the gallbladder plus a rim sign, two cases; and 3) nonvisualization of the gallbladder plus an enlarged photon deficient area corresponding to the gallbladder fossa, four cases. A rim sign or an enlarged gallbladder fossa reflect the direct spread of inflammation from the gallbladder into the liver, causing impaired hepatocyte function. An enlarged gallbladder fossa may represent a later stage of a rim sign. Presumably tracer excretion by hepatocytes is affected initially by the inflammatory process, followed by impairment of tracer concentrating ability. Since the gallbladder may be suspended occasionally by a mesentery and not in contact with the liver, the secondary signs may be absent in acute gangrenous cholecystitis.