This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Abdominal Radiography, Subject name: Radiology
Sentinel loop on x-ray: 
Select and explain. 
A. Meckel's diverticulum, B. Acute cholecystitis, C. Acute mesenteric adenitis, D. Acute pancreatitis
D: Acute pancreatitis
Answer: D: Acute pancreatitis 
Explanation: Ans. (d) Acute pancreatitisRef: Bailey 26th ed. /1128-29* The most commonly recognized radiologic signs associated with acute pancreatitis include the following:# Air in the duodenal C-loop# The sentinel loop sign, which represents a focal dilated proximal jejunal loop in the left upper quadrant.# The colon cut-off sign, which represents distention of the colon to the transverse colon with a paucity of gas distal to the splenic flexure.