Diagnostic accuracy of computed tomography imaging of surgically treated acute acalculous cholecystitis in critically ill patients.

BACKGROUND: Acute acalculous cholecystitis (AAC) is a potentially fatal condition mainly affecting critically ill patients. Current experience from computed tomography (CT) findings in AAC is contradictory.

METHODS: CT images of 127 mixed medical-surgical intensive care unit patients were retrospectively reviewed for the following findings: bile density, thickness and enhancement of the gallbladder (GB) wall, subserosal edema, greatest perpendicular diameters of the GB, width of extrahepatic bile ducts, gas within the GB, ascites, peritoneal fat edema, and diffuse tissue edema. Forty-three of these patients underwent open cholecystectomy, and 8 patients revealed a normal GB, 26 an edematous GB, and 9 a necrotic AAC.

RESULTS: Abnormal CT findings were present in 96% of all the intensive care unit patients. Higher bile density in the GB body and subserosal edema was associated with an edematous GB (specificity, 93.6%; sensitivity, 23.1%). The most specific findings predicting necrotic AAC were gas in the GB wall or lumen, lack of GB wall enhancement, and edema around the GB (specificity, 99.2%, 94.9%, and 92.4%, respectively; and sensitivity, 11.1%, 37.5%, and 22.2%, respectively).

CONCLUSIONS: The frequency of nonspecific abnormal findings in the GB of critically ill patients limits the diagnostic value of CT scanning in detecting AAC. However, in the case of totally normal GB findings in CT, the probability of necrotic AAC is low.