正常老年人及老年前期海马、内嗅区MRI与组织学的研究

Comparative study of MRI and histology on hippocampus and entorhinal cortex in normal elderly and preelderly people

目的研究正常老化过程对人脑海马、内嗅区形态与组织学影响，为检测疾病状态下海马、内嗅区的改变提供参考依据。方法应用ＭＲＩ与组织学测量相对照的实验方法，ＭＲＩ测量２０例无明显神经系统疾病的人脑，在通过几个特定冠状层面上（前联合、乳头体及外侧膝状体），测量海马、内嗅区皮层厚度及面积；组织学方面应用图像分析仪进行神经元计数。结果在以上几个层面上，海马、内嗅区皮层厚度、面积以及相对应的神经元数量不随年龄增长而减小；应用相关分析统计法结果表明ＭＲＩ与组织学面积测量之间有明显相关性。结论正常老化过程中，不出现海马、内嗅区相应层面上的萎缩及神经元丢失；应用ＭＲＩ对某些疾病的早期诊断可以提供重要的参考依据。

Objective To study the effect of normal aging on human hippocampus and entorhinal cortex with the comparative method of MRI and histology. Methods MRIbased area measurements through several special coronal levels(anterior commisure, mamillary body and lateral genicular nucleus)of the hippocampus and entorhinal cortex were measured; the using imaging analyzer, we counted neuronal density of the hippocampus and entorhinal cortex on the same coronal levels. Results The MRIbased area measurements indicated that in normal aging, there was no significant agerelated atrophy in the hippocampus and entorhinal cortex. The result showed that the neuronal density kept constant during normal aging; while the MRIbased area measurements correlated with those after preparation. ConclusionIn the hippocampus and entorhinal cortex, there was without no the decrease of the volumes or the loss of the neurons on special levels during normal aging.It was considered that the MRIbased area measurements of the hippocampus and entorhinal cortex might be of value for early diagnosis of some degenerative diseases of the CNS.