Sonography of gangrenous cholecystitis.

Gangrenous cholecystitis is an acute surgical emergency, which requires early cholecystectomy. Differentiation of patients with gangrenous cholecystitis from those with non-gangrenous cholecystitis can be difficult, both clinically and with imaging. Careful attention to the following sonographic signs suggests the presence of gangrenous cholecystitis decreased focal wall perfusion on Color Doppler, irregular gall bladder mucosal outline, gall bladder wall thickening with signs of de-lamination, gas within the gall bladder, absence of calculi, and large peri-cholecystic collections. Both sonogram with color flow imaging and contrast-enhanced Computed tomography are complementary investigations to establish this important diagnosis in critically ill patients.