Figure 11c. Fibromuscular dysplasia in a 46-year-old man who had undergone transplantation 4 years earlier. The patient underwent MR angiography because of an elevated serum creatinine level and hypertension. (a, b) MPVR (a) and volume-rendered (b) images demonstrate the proximal transplant artery, which has an irregular beaded appearance, a finding that suggests fibromuscular dysplasia. (c) CO2 angiogram demonstrates corresponding vessel irregularity; however, there was no significant pressure gradient to warrant angioplasty. The patient subsequently underwent transplant biopsy, which demonstrated rejection.