Fig. 9

A 75-year-old man with a history of chronic kidney disease and type 2 diabetes mellitus presents with back pain and fever. (a) Axial and (b) coronal non-contrast CT scans of the abdomen demonstrates aneurysmal dilatation of the infrarenal aorta, with multiple pockets of gas within the aortic wall (arrow) and periaortic fat stranding (*), consistent with emphysematous aortitis. The patient underwent urgent excision of the mycotic aneurysm, with placement of an axillobifemoral bypass graft. The resected aortic wall grew Clostridium perfringens, a gram-positive, gas-forming anaerobic bacillus. Ao = abdominal aorta