Marshall V G, Bradley W G, Marshall C E, Bhoopat T, Rhodes R H
MR Imaging Laboratory, Hunington Medical Research Institutes, Pasadena, CA 91105.
Radiology. 1988 May;167(2):517-22. doi: 10.1148/radiology.167.2.3357964.
Focal and confluent areas of periventricular hyperintensity have been reported on magnetic resonance (MR) images in 30% of patients over 60 years of age. In order to better understand the pathologic basis of these lesions, the authors studied 14 formalin-fixed brains with MR imaging. Multiple focal areas of hyperintensity were identified in the periventricular white matter in three of the 14 brains studied (21%). Subsequent gross and microscopic pathologic examination of both hyperintense and normal-intensity areas was performed on 87 tissue sections. The larger lesions were characterized centrally by necrosis, axonal loss, and demyelination and therefore represent true infarcts. Reactive astrocytes oriented along the degenerated axons were identified at distances of up to several centimeters from the central infarct. This is called isomorphic gliosis and is associated with increased intensity on T2-weighted images that increases the apparent size of the central lesion.
据报道，在60岁以上的患者中，30%的人磁共振（MR）图像上出现脑室周围高信号灶和融合灶。为了更好地理解这些病变的病理基础，作者对14例用福尔马林固定的大脑进行了MR成像研究。在14例研究的大脑中有3例（21%）在脑室周围白质中发现多个高信号灶。随后对87个组织切片的高信号区和正常信号区进行了大体和显微镜病理检查。较大的病变中央表现为坏死、轴突丢失和脱髓鞘，因此代表真正的梗死灶。在距中央梗死灶数厘米远的地方可识别出沿变性轴突排列的反应性星形胶质细胞。这被称为同形性胶质增生，与T2加权图像上强度增加有关，从而增加了中央病变的表观大小。
