Perfusion-weighted magnetic resonance imaging in the assessment of haemodynamics following stent angioplasty in patients with symptomatic middle cerebral artery plaque stenosis at the M1 segment

The most effective strategy to assess changes in the brain haemodynamics of stent angioplasty in patients with symptomatic ischemia of the M1 segment of the middle cerebral artery (MCA) remains unknown. The purpose of the present study was to use perfusion-weighted magnetic resonance imaging (PWI) to evaluate the effect of stent angioplasty in treating patients with symptomatic MCA plaque stenosis. Stent angioplasty was performed on 23 patients with reduplicative transient ischaemic attack who were refractory to medical therapy. All patients had MCA plaque stenosis at the M1 segment. Brain PWI was obtained from four major regions of interest (ROIs) at the frontal parietal, temporal, lateral ventricle and basal ganglia lobes prior to and following stent implantation. In addition, cerebral blood flow (CBF), cerebral blood volume, mean transit time (MTT) and time to peak (TTP) parameters derived from PWI were calculated. All patients underwent digital subtraction angiography following surgery to confirm the patency. Computed tomography angiography or PWI was performed 1 week and 3 months post-surgery. According to pre-operative PWI, there was significant hypoperfusion in the symptomatic frontal parietal, temporal, lateral ventricle and basal ganglia lobes. By contrast, the regional CBF and CBF increased in the ROIs of the affected cerebral hemisphere 3 months after stent implantation (P<0.05 vs. pre-operative data). Additionally, post-operative MTT and TTP in the ROIs on the operative side were significantly shorter than pre-operative MTT and TTP (P<0.05). During the follow-up period, the frequency of transient ischaemic attack was reduced or disappeared in all patients during the follow-up. In conclusion, PWI enables an effective and objective assessment of haemodynamics prior to and following stent angioplasty in patients with plaque stenosis of MCA at the M1 segment.