Answer: Emphysematous Cholecystitis .
Emphysematous cholecystitis is an acute infection of the gallbladder wall caused by gas-forming organisms.Supine view of the abdomen shows air in the wall (blue arrows) of the gallbladder (GB). There is also a lucency within the lumen of the gallbladder suggesting air inside the lumen. Just superior to the gallbladder is another collection of air (red arrow) that represents a pericholecystic abscess. The yellow arrow points to PEG tube in the stomach.