Thirty-six patients with aortoiliac reconstruction were studied by magnetic resonance imaging (MRI) to determine the diameter, baseline signal, and subsequent magnetic signal characteristics of postoperative periprosthetic collection (PPC). Our study confirmed the presence of PCC in most cases (32/36). The diameter was significantly (p < 0.05) correlated with the type of disease being treated, the type of proximal anastomosis created, and whether or not drainage and postoperative transfusion were used. PPC usually disappeared within 3 to 6 months postoperatively. Modifications of magnetic signals T1 and T2 require approximately the same amount of time to diminish. During follow-up investigations in this series, there was one case of prosthetic infection characterized by the persistence of PPC and a strong T2 signal 6 months after surgery, the latter corresponding to incomplete or delayed healing. The MRI aspects of normal healing of aortic grafts were analyzed to correctly interpret the MRI aspects of complications in surgery of the aorta.