外部性脑积水与脑萎缩的CT鉴别诊断

CT Differential Diagnosis of External Hydrocephalus and Cerebral Atrophy

本文对３０例外部性脑积水（ＥＨ）和１０例脑萎缩（ＣＡ）的ＣＴ表现作回顾性对照分析。ＥＨ的ＣＴ特征为：双侧额顶区蛛网膜下腔对称局限性增宽，不伴有脑质、脑沟异常和脑室扩大；其脑室颅腔横径率（ＶＴ／ＳＴ率）小于１５％。ＣＡ的特征为：脑周蛛网膜下腔普遍性增宽，且伴有脑皮质变薄，密度减低，脑沟普遍加深和脑室明显扩大，其ＶＴ／ＳＴ率大于１５％。文中介绍并讨论了ＶＴ／ＳＴ率的测算方法和鉴别诊断意义。

The CT findings of 30 cases of external hydrocephalus(EH)and 10 cases of cerebral atrophy(CA)were retrospectively analysed.The EH main features were the widening of the subarachnoid space in the bifrontoparietal regions without sulci enlargment or ventricular dilatation;The transversal diameter ratio of ventricular to skull(VT/ST)was<15%.The main findings of CA were diffuse widening of the subarachnoid space distributed throughout the entire cerebrum with thinned and low-density of cerebral cortex,general deepness in sulcus and remarkable dilatation of ventricular;Its VT/ST ratio was>15%,The authors suggested the way of measuring VT/ST and discussed its value of differential diagnosis.