Xu Weixingzi, Wen Jianbo, Sun Chong, Cao Jiawen, Li Yuxin, Geng Daoying
Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China.
J Comput Assist Tomogr. 2018 Jul/Aug;42(4):510-516. doi: 10.1097/RCT.0000000000000712.
The aims of the study were to analyze the conventional and diffusion-weighted MRI (DWI) of mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) and to investigate underlying mechanisms.
Features of 58 acute and 68 chronic stroke-like lesions as well as global brain abnormalities of 40 Chinese MELAS patients were analyzed.
Gyriform DWI hyperintensity with decreased apparent diffusion coefficient (ADC) and patchy DWI hyperintensity with normal ADC were noted in 56 of 58 and 2 of 58 cortical regions of acute lesions, respectively. High ADC and mix of low and high ADC were observed in 51 of 58 and 5 of 58 affected subcortical white matters, respectively. Lacunar infarcts existed in 23 of 40 patients. Among 17 patients who have been followed, recurrence, progression, and progressive atrophy were noted in 8, 9, and 4 cases, respectively.
This study demonstrates the conventional and diffusional MRI features of MELAS, suggesting a model of acute stroke-like lesions in which the cortex manifest with cytotoxic edema and the subcortical area with vasogenic edema.
本研究旨在分析线粒体脑肌病伴乳酸血症和卒中样发作（MELAS）的传统磁共振成像（MRI）及扩散加权成像（DWI）表现，并探究其潜在机制。
分析了40例中国MELAS患者的58个急性和68个慢性卒中样病灶的特征以及全脑异常情况。
在58个急性病灶的皮质区域中，分别有56个和2个区域出现脑回状DWI高信号且表观扩散系数（ADC）降低，以及斑片状DWI高信号且ADC正常的情况。在58个受影响的皮质下白质区域中，分别有51个和5个区域观察到ADC升高以及ADC高低混合的情况。40例患者中有23例存在腔隙性梗死。在17例接受随访的患者中，分别有8例、9例和4例出现复发、病情进展和进行性萎缩。
本研究展示了MELAS的传统MRI及扩散成像特征，提示了一种急性卒中样病灶模型，即皮质表现为细胞毒性水肿，皮质下区域表现为血管源性水肿。
