Previous CT-scan (performed 10 weeks earlier, a few week following Whipple's surgery) shows an infra-renal abdominal aortic aneurysm, without air crescent nor peri-aortic fat stranding.
There are many other, less relevant findings, as this CT-scan was done in the post-operative period of a Whipple surgery for pancreatic adenocarcinoma. There is a post-operative collection near the surgical bed, which completely regressed in later studies.