外部性脑积水的CT诊断及临床应用价值

目的 探讨外部性脑积水(EH)的CT特征及临床应用价值。材抖与方法 回顾分析临床资料完整的66例外部性脑积水的CT表现及测量脑室颅腔横径(VT／ST)率。结果 特发性者34例(51．52％)，32例继发性主要原因为缺氧缺血性脑病，为18例(占56．25％)。EH的CT特征为：大脑半球叶间裂前部增宽(≥6mm)，额顶区蛛网膜下腔对称性增宽(≥5mm)，可伴顿顶区脑沟回增宽加深，严重者可伴双侧侧裂池增宽及鞍上池增大，脑室不扩大或仅轻度扩大，VT／ST率小于15%。结论 根椐患儿短期内有头围异常增大，前囱膨隆，抽搐以及特有的CT表现，对EH的诊断并不困难，CT检查对EH的临床诊断、病程观察及指导治疗具有重要价值。

Evaluation of CT Diagnosis and Clinical Application In External Hydrocephalus

Objective To evaluate CT diagnosis and clinical appli-cation in external hydrocephalus(EH). Methods The CT features andcomplete clinical data of 66 cases of EH were retrospectively analyzed.The ratio of the transverse diameter of the ventricle and skull wasmeasured in all the cases. Results Among the 66 cases,34 cases werediagnosed as idiopathic EH and 32 cases as secondary EH tohypoxicischemic encephalopathy.The characteristic CT features of EHwere as follows;(1)Widening of the subarachnoid space in thebifrontoparietal regions,(2) Widening of the interhemispheric fissure,(3) Widening and deepening of the sulcus and gyrus in the bifrontoparietalregions in some cases,(4) Widening and enlargement of the cistern ofbilateral fossae and suprasellar cistern in the severe cases,(5)Little orslight enlargement of the cerbral ventricles and(6)The ratio VT/STwas smaller than 15%. Conclusion Combining the CT features withthe clinical findings such as enlargement of the head circumference ina short period,expansion of the anterior fontanel,seizures of convulsion,etc,a physician is easy to diagnose EH.CT plays an important role inthe diagnosis,observation and management of the patients with EH.