大脑中动脉粥样硬化斑块的影像学特征

Imaging characteristics of middle cerebral artery atherosclerotic plaque

目的应用高分辨率磁共振(HR-MRI)管壁成像技术比较症状性与无症状性大脑中动脉(MCA)粥样硬化斑块的影像学特征。方法根据MCA支配区是否有急性脑梗死或TIA,将116例有MCA粥样硬化狭窄的患者分为症状组80例及无症状组36例。采用3.0 T HR-MRI检查MCA斑块影像学特征。结果症状组患者环形斑块比率明显高于无症状组(P=0.019)。症状组和无症状组斑块信号类型在T_1WI、T_2WI和STIR上差异无统计学意义(均P>0.05)。与无症状组比较,症状组斑块明显强化比率显著升高(P<0.001),无强化及轻度强化比率显著降低(均P<0.001)。结论 HR-MRI可以清晰显示MCA粥样硬化斑块形态。症状性MCA斑块以环形多见,斑块明显强化;非症状性MCA斑块以弧形为主,斑块多无强化或轻中度强化。两组斑块信号在各序列无明显差异。

Objective To Compare the imaging characteristics of symptomatic with non symptomatic middle cerebral artery（ MCA） atherosclerotic plaque by using high-resolution magnetic resonance imaging（ HR-MRI）.Methods According to the acute cerebral infarction or TIA in the ipsilateral middle cerebral arterial territory,116 patients with MCA atherosclerotic stenosis were divided into symptomatic group（ 80 cases） and non symptomatic group（ 36 cases）. Imaging characteristics were checked by 3. 0 T HR-MRI. Results The ratio of annular plaques in symptomatic group was significantly increased than that in non symptomatic group（ P = 0. 019）. There was no significant differences in the plaques signal types on T1 WI,T2 WI,and STIR sequences between the two groups（ all P 〉 0. 05）. Compared with non symptomatic group,the rate of marked enhancement in symptomatic group was significantly increased（ P 〈 0. 001）,and the rates of no enhancement and mild enhancement were significantly decreased（ all P 〈 0. 001）. Conclusions HR-MRI can clearly show the morphology of MCA atherosclerotic plaques.Symptomatic MCA plaques are usually represented as annular plaque and significantly enhanced. The asymptomatic MCA plaques are arcs,with no enhancement or mild to moderate enhancement. There is no significant difference between the two groups of plaque signals in each sequence.