In endurance athletes, leg complaints upon maximal exercise caused by flow limitations in the iliac arteries are frequently encountered. We theorize that functional kinking of the vessels, which occurs especially during hip flexion, may be a cause for such flow limitations. Conventional diagnostic tests cannot demonstrate such kinkings. Using gadolinium-enhanced magnetic resonance angiography, a 3D dataset of the aorto-iliac arteries could be obtained with the hips flexed. An image processing procedure was developed using a new segmentation algorithm to be able to use standard surface rendering techniques to visualize the arteries with an improved 3D appearance. These techniques were applied in the current study in 42 endurance athletes with documented flow limitations in the iliac arteries. As a control group 16 national level competitive cyclists without flow limitations in the iliac arteries were studied. Forty-six affected legs were examined in 42 patients. In all patients and reference persons image quality was adequate and the segmentation algorithm could be applied. In 22 affected legs (48%) a kinking in the common iliac artery could be demonstrated, compared with one leg (3%) in the control group. In 13 affected legs (28%) a kinking in the external iliac artery could be demonstrated, compared with three legs (9%) in the control group. It can be concluded that flow limitations in the iliac arteries in endurance athletes are associated with kinkings in the common and/or the external iliac arteries. Magnetic resonance angiography with the hips flexed followed by this newly developed segmentation algorithm is effective to visualize and score these kinkings.