颈动脉壁易损斑块与再发缺血性脑卒中间隔时间关系的磁共振研究

目的探讨MR定义的颈动脉易损斑块与再发缺血性脑卒中的关系,评价颈动脉磁共振成像在缺血性脑卒中二级预防中的临床应用价值。方法50例有明显症状的再发脑卒中患者在再次发病7天内进行检查。使用的西门子Sonata1.5T扫描仪与四通道专用颈动脉线圈。先进行2DTOF扫描对颈动脉分叉处进行定位,然后分别对分叉上下各2cm的颈总动脉与颈内动脉进行垂直于血管走行的连续轴位扫描。任意连续两个层面发现易损斑块特征即可诊断。比较易损斑块组与非易损斑块组的脑卒中间隔时间,以及1年以内再发脑梗死与1年以上再发脑梗死患者之间的易损斑块检出率。以血压、血糖、血脂等作为协变量构建Cox生存分析模型研究斑块对再发脑卒中间隔时间的影响。结果有MRI表现易损斑块的病人再发脑卒中的时间明显短于无易损斑块患者(296.2vs1623.8,P<0.001)。在1年以内再发脑梗死的病人中,易损斑块的检出率高于1年以上再发脑梗死的病人(80%vs13.3%,P<0.001)。经过血压、血糖、血脂的校正,发现易损斑块是迅速再发脑梗死的重要危险因素(HR=5.596,P<0.001,95%CI2.766～11.326)。结论颈动脉存在易损斑块与快速再发缺血性脑卒中相关。MRI作为一项动脉粥样硬化斑块的定性检查证明了它在缺血性脑卒中二级预防中的潜在价值,为将来使用MRI前瞻性评价卒中二级预防的效果提供了重要的依据。

Vulnerable lesion correlates to accelerated recurrence of cerebral infarction: carotid MR imaging study

Objective To test the hypothesis of a MRI-defined vulnerable plaque relating to quick reoccurrence of cerebrovascular events and evaluate potential usage of MRI in secondary prevention of ischemic stroke. Methods Fifty symptomatic participants were recruited from patients who suffered from second time cerebral infarction. Patients were imaged within 7 days after reoccurrence of cerebral infarction. The type of carotid artery lesion was classified according to the signal in it. Then, we compared the interval of cerebral infarction between patients with and without vulnerable lesion and the prevalence of vulnerable lesion in patients with different intervals. A Cox proportional hazards model was constructed to calculate the influence of vulnerable lesion on the interval of cerebral infarction. Results The mean recurrence interval of patients with vulnerable lesion was shorter than that of patients without vulnerable lesion (296.2 vs 1623.8, P<0.001). Vulnerable lesions were detected more frequent in patients with recurrent cerebral infarction within one year (80% vs 13.3%, P< 0.001). The patients with vulnerable lesion had a 5.596-fold higher HR (HR=5.596, P<0.001, 95%CI 2.766-11.326) than those without it after adjustment of risk factors. Conclusion MRI-defined vulnerable lesion in carotid artery related to accelerated recurrent cerebral infarction. MRI demonstrated its potential value in secondary prevention of cerebral infarction.