MRI梯度回波对脑微出血的检出及其临床意义

Cerebral microbleeds detected on T2-weighted gradient echo magnetic resonance and its clinical significance

目的 探讨T2加权梯度回波磁共振成像对脑微出血的诊断价值,以及脑微出血的临床意义.方法 收集2010年1月至2012年6月在浙江省丽水市中心医院门诊或住院治疗的634例临床疑有脑卒中患者,通过常规MRI T1WI、T2WI及T2加权梯度回波序列（T2WI）检查,分析脑微出血灶分布,并进行随访观察.结果 149例发现脑微出血灶,共1140个,好发部位依次为皮层-皮层下471个（41.32％）、基底节289个（25.35％）、丘脑199个（17.46％）、脑干90个（7.89％）、小脑91个（7.98％）.149例患者中137例脑内均有不同程度缺血性改变,表现为两侧基底节区、侧脑室旁白质区、脑干异常信号,T1WI呈等、低信号,T2WI、FLAIR呈高信号.其中23例患者合并急性脑梗死,5例患者出血性卒中合并脑微出血.本组12例缺血性卒中合并脑微出血患者,2～6个月后,脑内出现出血病灶.结论 T2加权梯度回波磁共振成像在检出脑微出血灶方面有明显的优势,脑微出血提示存在脑出血的危险.

Objective To explore the diagnostic value of T2-weighted gradient-echo magnetic resonance imaging （MRI） in cerebral microbleeds （CMBs） and its clinical significance.Methods The distribution of CMBs and follow-up observations were performed by routine T1WI,T2WI and T2-weighted gradient echo sequence in 634 patients clinically suspected for stroke.Results In 149 patients,a total of 1140 CMBs occurred predominantly in cortex-subcortical area （n =471,41.31%）,basal ganglia （n =289,25.35%）,thalamus （n =199,17.45%）,brain stem （n =90,7.89%） and cerebellum （n =91,7.98%）.Among them,137 patients had various degrees of ischemic brain changes,displayed iso-intensity or hypo-intensity on T1WI,hyper-intensity on T2WI and FLAIR in basal ganglia,white matter around sided ventricle and brain stem.There were 23 patients with cerebral infarction and 5 with CMBs after hemorrhagic brain stroke.And 12 of them had new hemorrhagic stroke in 2-6 months.Conclusion T2-weighted gradient echo MRI has obvious advantages in the detection of CMBs.The presence of CMBs suggests a risk of cerebral hemorrhage.