Research for Pathophysiology of Diffuse Cerebral White Matter Disease -Evaluation with MRI of Autopsied Brain and Diffusion Weighted MRI-

1.对95例脑组织进行了尸检，并与全脑显微切片的组织学结果进行了比较。在12例阿尔茨海默病、Binswanger病、CreutzFeldt-Jakob病、血管内淋巴瘤和帕金森氏病患者的脑组织中观察到弥漫性白质病变。在Binswanger病中，脑室周围可见弥漫性白质损害，而卷曲白质和U纤维相对保留。阿尔茨海默病患者，颞叶皮质下白质和顶叶皮质下白质的髓鞘纤维丢失和胶质增生明显，额叶和顶叶皮质下白质相对较轻。MR成像清楚地显示了组织学检查所观察到的有或无U纤维受累的白质病变。2.对5例正常人、8例阿尔茨海默病(AD)和8例Binswanger型血管性痴呆(VD)患者进行磁共振弥散加权成像。计算各向异性分数(FA)和表观弥散系数(ADC)的平均值，分别在膝部和压部，大脑前部和后部白质。AD组和对照组在任何地区的痕迹图像ADC值均无统计学差异。AD患者后部白质FA值明显低于对照组。各地区VD患者的FA值均显著低于AD组和对照组。VD组前部脑白质FA值低于后部脑白质。分数各向异性有助于VD与AD的鉴别诊断。

1. We performed postmortem MR examinations of 95 brains and compared them to the histology of the whole brain microscopic sections. Diffuse white matter lesions were observed in 12 brains with Alzheimer disease, Binswanger disease, Creutzfeldt-Jakob disease, intravascular lymphomatosis, and Parkinson's disease. While diffuse white matter lesions were observed around the periventricular regions in the Binswanger disease, convolutional white matter and U-fibers were relatively preserved. In the Alzheimer disease, loss of myelinated fibers and gliosis was marked in the temporal subcortical white matter and extreme capsule and was relatively mild in the frontal and parietal subcortical white matter. MR imaging clearly demonstrated such white matter lesions with or without U-fiber involvement observed by histological examination. 2. Diffusion weighted MR imaging was performed in 5 control subjects, 8 patients with Alzheimer's disease (AD) and 8 patients with Binswanger type vascular dementia (VD). Mean values of the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were calculated in the genu and splenium of the corpus callosum, anterior and posterior cerebral white matter. There were no statistically significant differences in ADC values of the trace image between the AD and controls in any regions. FA value of the posterior white matter in patients with AD was significantly lower than that of controls. FA value in the patients with VD was significantly lower than that of the AD and controls in any regions. In the VD group, FA value of anterior white matter was lower than that of posterior white matter. The fractional anisotropy may be useful in the differentiation diagnosis of VD from AD.