可复性后部脑病综合征的MR影像分析

MRI diagnosis of posterior reversible encephalopathy syndrome

目的探讨可复性后部脑病综合征(PRES)的MRI特点。材料与方法回顾性分析16例临床和影像学诊断的PRES患者的MR影像资料,全部患者行常规MRI平扫和DWI检查,5例同时行MRV检查,11例患者对症治疗后行MRI复查。结果病变多发,16例患者MRI平扫共检出73个病灶,多位于皮层下白质,表现为T1WI稍低、T2WI稍高信号,于T2-FLAIR上呈高信号。最常累及顶、枕叶(88.5%),其次为额叶(61.3%),小脑半球(31.3%),颞叶(30.1/%),基底节(28.7%),脑干(17.3%)。1例患者伴有脑内多发出血灶。除出血灶外,余病变于DWI上呈等或稍高信号,多数于ADC图上呈高信号;仅于胼胝体压部发现一病变于ADC图上呈低信号。5例颅脑MRV检查均未见确切异常。经治疗后11例患者行MRI复查,显示病变数目较前明显减少,残余病灶ADC值[(0.937±0.086)×10–3mm2/s]较前次检查[(1.036±0.186)×10–3mm2/s]减低(P=0.005),更接近正常脑组织ADC值[(0.832±0.078)×10–3mm2/s]。结论 PRES的颅脑MRI表现较具有特征性,DWI及MRV检查对该病的诊断及鉴别诊断具有重要意义,MRI复查对PRES疗效评价具有重要价值。

Objective： To investigate the MRI findings of posterior reversible encephalopathy syndrome（PRES）.Materials and Methods： The MRI datas of 16 patients were analyzed retrospectively.16 cases were examined by MRI,5 with MRV examination at the same time,11 with systematic treatment were reviewed by MRI.Results： Lesions were multiple,16 cases of the MRI scan detected 73 lesions,Most of them were located in the subcortical white matter.The lesions showed slightly hypointensity on T1WI and slightly hyperintensity on T2WI.Most often affected parietal-occipital lobe（88.5%）,followed by frontal lobe（61.3%）,cerebellum（31.3%）,temporal lobe（30.1%）,basal ganglia（28.7%） and brain stem（17.3%）.1 with multiple focal hemorrhage in the brain.Except the focal hemorrhage,other lesions showed slightly high signal on DWI,most of the lesions showed high signal on ADC map,Only one lesion in corpus callosum revealed hypointensity on ADC map.There were no abnormally findings in 5 MRV examinations.After treatment,11 MRI showed significant lesion number decrease.Compared to the previous inspection [（1.036±0.186）× 10–3mm2/s],residual lesions＇ ADC values [（0.937±0.086）×10–3mm2/s] were decreased,and closer to the ADC values of normal brain [（0.832±0.078） ×10–3mm2/s）.Conclusions： The MRI imaging of PRES is characterized,DWI and MRV have great significance for the diagnosis and differential diagnosis of PRES,and the follow up MRI scan of PRES after treatment has important value to the therapeutic effect.