Computed tomography at the time of first examination (left, three-dimensional construction; middle, transverse plane; right, sagittal plane). A dissecting arterial aneurysm, with a maximum diameter of 12.3mm (compared with 6.6mm at an unaffected site), was localized approximately 1.5 and 5cm distal to the ostium of the superior mesenteric artery. A false lumen was partially occupied by a thrombus. Distal to the occlusion, the arterial wall was irregularly shaped, with narrow and wide sections. An irregular shaped arterial wall was also observed in the inferior mesenteric artery. Arterial dissection with thromboembolism was also observed in the left renal artery, accompanied by ipsilateral renal infarction.