Blood volume flow quantification of the brain-supplying circulation in fibromuscular dysplasia using 2D cine phase-contrast MRI.

To determine blood volume flow (BVF) in the brain-supplying arteries in patients with fibromuscular dysplasia (FMD), we used two-dimensional cine phase-contrast MR blood flow quantification to evaluate haemodynamic compromise. Nine patients with angiographically proven FMD (mean age, 46.7+/-10.4 years) of the cervical and intracranial arteries were examined using two-dimensional phase contrast MR to measure blood flow in the carotid arteries and the basilar artery (BA). Quantitative BVF results were compared intra- and inter-individually and also with the results of 15 age-matched normal controls. No patient showed evidence of acute or chronic infarction of the brain. FMD lesions were found in a total of 19 arteries (internal carotid artery: n = 14; vertebral arteries: n = 5). Five patients demonstrated severe stenoses of cervical vessels; four patients showed only mild or up to moderate stenoses. Total brain BVF in all FMD patients reached high-normal values compared with normal controls (747+/-64 ml min(-1) vs 682+/-38 ml min(-1)). In the five patients with severe stenotic lesions, blood flow was reduced in stenotic vessels and higher in the non-haemodynamically relevant stenosed cervical vessels. BVF was normal in the four patients with mild and moderate stenoses. By quantifying blood flow, we demonstrated for the first time changes (which can be severe) in the BVF of the brain-supplying arteries in FMD. Individual differences are associated with the haemodynamic relevance of the FMD lesions. Total BVF in patients with severe FMD was not decreased but maintained or even increased, possibly as an overcompensation.