脑后部可逆性脑病综合征与MELAS的磁共振特征对照研究

目的对脑后部可逆性脑病综合征(PRES)的磁共振特征进行分析并与线粒体脑肌病伴高乳酸血症和卒中样发作综合征(MELAS)进行对照,以进行诊断与鉴别诊断。方法收集21例PRES和6例MELAS患者,所有患者均行磁共振检查,回顾性分析和比较它们在MRI上的影像特征(发病部位,信号强度,功能成像特点等)。结果 21例PRES病灶主要位于皮质下白质区,13例同时累及皮质;6例MELAS病灶位于皮质及皮质下白质。DWI上,19例PRES患者病变表现为稍低信号;MELAS综合症患者,急性期病变为高信号,缓解期为等信号。2例PRES表现为局部脑血流量(CBF)减低;2例MELAS局部CBF轻度增高。结论详细的磁共振检查和分析有助于PRES和MELAS的鉴别。

Comparative study of MRI characteristics between posterior reversible encephalopathy syndrome and MELAS syndrome

Objective:To compare the MRI characteristics of posterior reversible encephalopathy syndrome with that of MELAS syndrome.Materials and Methods:Twenty-one patients with PRES and 6 patients with MELAS syndrome were recruited.MRI findings,including the location,signal intensity,and functional characteristics,were retrospectively analyzed.Results:Lesions in the subcortical white matter were found in 21 patients with PRES,and involved cortex in 13 patients.Lesions located in the cortex and subcortical were revealed in 6 patients with MELAS.On DWI,low signal intensity was revealed in 19 patients with PRES;high signal intensity was shown in acute MELAS with isointensity in remission.Decreased cerebral blood volume(CBF) was found in 2 cases of PRES.Increased CBF in 2 cases of MELAS syndrome.Conclusion:Detailed MRI analysis is helpful for the differentiation of PRES and MELAS syndrome.