Outpouching from 2nd part of duodenum, causing compression of CBD, proximal upstream dilation and mild prominence of proximal intrahepatic biliary radicals. A rim of fluid is seen surrounding the lesion with a focus of air; likely duodenal diverticulum with diverticulitis. 

Pancreas is heterogeneous in appearance with peripancreatic fat stranding, fluid, perinephric fat stranding and mild ascites consistent with acute pancreatitis.

Above findings are consistent with Lemmel syndrome.