线粒体脑肌的MRI表现特征及其诊断价值

MR Imaging Manifestation and Its Value in Diagnosing Mitochondrial Encephalomyopathy

目的:总结线粒体脑肌病的MRI表现特征并分析磁共振在线粒体脑肌病诊断中的价值。方法:搜集2005年1月～2007年7月经临床及病理证实的线粒体脑肌病患者资料21例,男5例,女16例。所有病例均行常规MRI检查(平扫加增强扫描),7例患者行磁共振波谱检查。结果:21例中有17例患者脑内病灶均表现为T1WI低信号、T2WI高信号,病变主要累及颞、顶、枕叶皮层、及深部灰质核团(以基底节多见),部分患者伴有不同程度的脑萎缩,病灶对称或不对称,且具有多发性,迁移性和与血管分布区不一致性;4例患者头部常规扫描仅见轻度脑萎缩。FLAIR及DWI序列能更清楚和准确显示较隐匿的病灶,7例磁共振波谱检查表现为病变区、无信号异常的脑区和/或脑室系统均可见较特征性的乳酸峰。结论:线粒体脑肌病的MRI表现有一定的特征性,磁共振成像(包括DWI、FLAIR、MRS)在线粒体脑肌病的诊断、鉴别诊断以及对该病代谢物改变的检测方面均具有重要的价值。

Objective：To evaluate the MR imaging manifestation in patients with mitochonclrial encephalomyopathy and to analyze the value of the MR in the diagnosis of mitochonclrial encephalomyopathy. Methods： Data of 21 cases with mitochonclrial encephalomyopathy confirmed by clinic and pathology from 2005-2007 were collected and analyzed. All patients, 5 male and 16 female, had the routine MR examination （plain and/or enhanced scans）, and /or diffusion weighted image （DWI） and/or FLAIR, 7 eases also had the MRS examination. Results： 17/21 eases with mitochondrial encehalomypathy showed low signal intensity on T1 WI and high signal intensity on T2 WI, the lesions involved the cortical layer of the temporal,parietal and occipital lobe and the deep gray matter nucleus （especially in the basal ganglia）. The distribution of the lesions was symmetric or asymmetric,multiple,migrating and variable,and the location was not corresponding with the vascular supply territories. Four cases only presented slight encephalatrophy without abnormal signal being detected in the routine MR examination. The FLAIR and DWI sequence could detect the inside lesions clearly and precisely. In the 7 eases who had the MRS examination,the distinctive lactic acid peak could be detected in the brain regions and/or the ventricular system with or without abnormal intensity. Conclusion： MR imaging of mitochondrial encephalomyopathy has some characteristics. The MR （MRS.FLAIR and DWI） plays an important role in the early diagnosis,differential diagnosis and in detecting the metabolism changes of mitochondrial encephalomyopathy.