Abstract:Objective: To evaluate the CT angiography(CTA) in demonstrating the arc of Riolan. Materials and Methods: Fourteen cases with the arc of Riolan were analyzed retrospectively. Among them, there were 9 male and 5 female patients, aged from 19 to 80 years(averaged 52.1 years). Five females suffered from Takayasu’s arteritis, while eight males had atherosclerosis and/or hypertension, one young male suffered from abdominal aortic coarctation. Results: Abdominal aorta occlusions were demonstrated in seven cases. SMA occlusions were found in two, seven cases showed stenosis, and five cases were normal. IMA occluded in six patients, stenosed in three cases, normal in five cases. The calibers of Riolan’s arc were 4 to 10mm, with an average of 6.9mm. Conclusion: The arc of Riolan can be demonstrated by CTA among those suffered from multiple abnormalities in abdominal vessels, and represents a significant stenosis or occlusion somewhere in mesenteric circulation. It is valuable for treatment procedures.