Hot rim sign on hepatobiliary scintigraphy (Tc99m-HIDA ) is seen in ?

* Increased Pericholecystic hepatic band of radio tracer activity called Rim sign. * A rim of increased hepatic activity directly adjacent to the gallbladder fossa in association with non visualization of the gall bladder is a specific sign of acute cholecystitis paicularly associated with gangrene and perforation . Below CT Image Shows Emphysematous Cholecystitis with Necrosis and Air within the wal of GB.It is surgical Emergency with high risk of GB perforation and moality.