How is imaging for acute pancreatitis?

Plain film abdomen (colon cutoff sign, sentinel loop, generalized bowel ileus, others [soft tissue epigastrum density, pancreatic calcifications, opaque GS, pleural effusion]) US (fails to image pancreas complete, superior to CT visualizing gall bladder and gall stones, - US doesn't R/O gall stone [only 50% are positive], detects extrapancreatic dilation, pancreatic edema and fluid, can give false info due to bowel gas) Contrast CT (Gold STD, indicated in sus of dx, ac pancreatitis clinically not improved for 2-3 days, sus of complications [peripancreatic fluid, necrosis, cysts])