523例正常枕大池CT图像分析──兼谈巨型枕大池、枕大池蛛网膜囊肿及Dandy－Walker畸形的CT图像鉴别诊断

本文研究了５２３例正常枕大池的ＣＴ图像，并讨论了巨型枕大池、枕大池蛛网膜囊肿及Ｄａｎｄｙ－Ｗａｌｋｅｒ畸形的ＣＴ鉴别诊断。作者将正常枕大池分为５种类型：①不规则型；②类圆型；③点状；④分裂型；⑤不可见型。作者对巨型枕大池、枕大池蛛网膜囊肿和Ｄａｎｋｙ－Ｗａｌｋｅｒ畸形的ＣＴ图像特点分别作了描写，并提出：巨型枕大池一般均为正常生理变异，不宜行手术治疗。

CT IMAGE ANALYSIS IN 523 CASES OF NORMAL CISTERNMAGNA

CT images of 523 cases of normal cisternmagna were studied , and the differ-ent diagnosis of huge cisternmagna, arachnoid cyst in cistermagna and Dandy-Walker syn-drome was discussed. The author divided the cisternmagna showed by CT into five groups:①Irregular type 327 cased,②Circular-like type 75 cases,③Pot-like type 48 cases,④Divisiontype 22 cases,⑤Invisible type 71 cases.The author believed that most of huge cisternmagnawere normal physiologic variation,not suitable to operation. The author indicated the fea-tures of huge cisternmagna,arachnoid cyst and Dandy-Walker syndrome as following; Hugecisternmagna:irregular morphosis,no change in size,location or morphology in the 4th ven-tricle,and no enlargement in the lateral ventricle and the 3th ventricie. Arachnoid cyst:the4th ventricle was compressed and deformed and moved forward,the lateral ventricle and the3th ventricle enlarged. Dandy-Warlker syndrome:Large low-density area in postcranial fos-sa.Cerebellar hemisphere departed and was pushed forward.Vermis atrophied even disap-peared.Lateral ventricle and the third ventricle enlarged symmetrically. Because the cyst it-self was the forth ventricle enlarged greatly,there was no sign of the forth ventricle outsidethe cyst.