The Department of Radiology, Peking University First Hospital, Center for Functional Imaging, Peking University, Beijing, People's Republic of China.
Neuroradiology. 2011 Apr;53(4):227-32. doi: 10.1007/s00234-010-0729-y. Epub 2010 Jun 17.
The exact mechanism of the mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) remain unclear. Diffusion-weighted imaging (DWI) is a magnetic resonance (MR) imaging technique for studying the pathophysiologic change of the MELAS. The purpose of the study is to see whether the apparent diffusion coefficient (ADC) of MELAS in the non-affected areas is different from the ADC of the normal subjects and to speculate the pathophysiological mechanisms of the MELAS.
Sixteen cases of MELAS were retrospectively analyzed. Thirty healthy subjects were chosen to constitute the control group. All of them were performed on the 3.0T whole-body MR scanner with axial view T2 fluid attenuated inversion recovery (flair), T2-weighted imaging, T1flair, and DWI. An ADC map was reconstructed in the workstation. Two to five regions of interest were put in the non-affected frontal lobe and basal ganglia. All data took statistical analysis.
There were significant differences between the ADC of the patients with MELAS and the controls in the non-affected areas, including the superior frontal gyrus, precentral gyrus, corpus striatum, thalamus, and white matter of the semi-oval centrum.
ADCs in the non-affected areas of the patients with MELAS are higher than those of the normal subjects. Pathological changes take place in the non-affected areas of the patients with MELAS.
线粒体肌病、脑病、乳酸酸中毒和卒中样发作（MELAS）的确切机制仍不清楚。弥散加权成像（DWI）是一种用于研究 MELAS 病理生理变化的磁共振（MR）成像技术。本研究的目的是观察 MELAS 非受累区的表观弥散系数（ADC）是否与正常对照者不同，并推测 MELAS 的病理生理机制。
回顾性分析 16 例 MELAS 患者。选择 30 名健康志愿者作为对照组。所有患者均在 3.0T 全身 MR 扫描仪上进行轴位 T2 液体衰减反转恢复（FLAIR）、T2 加权成像、T1FLAIR 和 DWI。在工作站上重建 ADC 图。在非受累的额叶和基底节区放置 2 至 5 个感兴趣区。对所有数据进行统计学分析。
MELAS 患者非受累区的 ADC 与对照组存在显著差异，包括额上回、中央前回、纹状体、丘脑和半卵圆中心的白质。
MELAS 患者非受累区的 ADC 高于正常对照者。MELAS 患者的非受累区存在病理变化。
