Gangrenous cholecystitis: diagnosis by ultrasound.

Sonographic findings were analyzed in 19 patients with surgically proved gangrenous cholecystitis. In 8 patients (42%), there were no specific features that would allow differentiation from typical uncomplicated acute cholecystitis. However, in 11 patients (58%) atypical findings were present, including intraluminal membranes and/or marked irregularities of the gallbladder wall. These features are unusual in uncomplicated acute cholecystitis and should prompt close clinical observation for possible gangrenous cholecystitis.