The pancreas is the largest gland in the human body, with a long and narrow shape, about 12-16cm long, 3-4cm wide, 1.5-2.5cm thick, weighing about 80g, located in the retroperitoneum of the epigastric region, spanning the 1st-2nd lumbar vertebrae, and can be divided into four parts: the head, the neck, the body and the tail. The head and neck were on the right side of the abdominal midline and resided in the duodenal curvature. The body and tail are on the left side of the abdominal midline, adjacent to the greater curvature of the stomach, the splenic hilum and the left renal hilum. In pancreatitis, there is blurring of the peripancreatic fat space, loss of the interstitial space, and blurring of the pancreas due to inflammatory exudation. Neighboring structures are involved: anterior and perirenal fascia, omental sac, paracolic groove, duodenal ring, mesenteric root, and pelvis.