CT chest and abdomen with contrast
After thirteen days CT shows in the middle lobe a thin walls cavity containing a little “fungus-ball” mass with the lucency that surrounding it: the "crescent sign". Right pleural effusion is present with passive atelectasis of the lower lobe. In abdomen there is large fluid collection containing gas bubbles in pancreatic bed due to abscess complicating acute pancreatitis with inflammatory infiltration of peripancreatic fat and gallstones.