Computed tomographic observations in periaortitis: a hypothesis.

Eight patients with features of retroperitoneal fibrosis are presented. The computed tomographic findings in these patients demonstrate the different in vivo appearances which may be encountered. In all eight patients the fibrotic process was centred on the lower aorta and encompassed the common iliac arteries to a variable extent. In no patient was a predisposing cause found, although in two the aorta was aneurysmal. We believe that these appearances illustrate the range of a single condition, periaortitis, which may well be due to an immune reaction to atheromatous material.