目的认识颅内蛛网膜囊肿的ＣＴ表现。方法回顾性分析３４例颅内蛛网膜囊肿的ＣＴ平扫和６例脑池造影ＣＴ扫描资料。结果颅内蛛网蟆囊肿ＣＴ特征如下：１．颅内蛛网膜囊肿好发于外侧裂池、枕大池、大脑半球凸面积和桥小脑角池；２．囊肿可呈多边形（１３／３４）、类圆形（１９／３４）和半圆形（２／３４），边缘清晰；３．囊肿呈水样密度，ＣＴ值１．６～１７．０Ｈｕ，增强扫描不强化；４．后颅凹和大脑半球间裂蛛网膜囊肿常出现占位效应，而外侧裂池和大脑凸面囊肿较少出现占位效应；５．局部颅板常受压迫变薄（２２／３４）；６．脑池造影即刻ＣＴ扫描，造影剂未充盈囊肿，延迟１．５～４．５ｈ时扫描，见造影剂充盈囊肿，边缘光滑锐利。结论ＣＴ扫描对颅内蛛网膜囊肿是一种有效的诊断和鉴别诊断手段，脑池造影ＣＴ扫描可以充分地显示蛛网膜囊肿与蛛网膜下腔是否相通和通畅程度，对于神经外科治疗方案的选择有指导作用 Objective To understand the CT findings of intracranial arachnoid cyst. Methods A retrospective analysis of 34 cases of intracranial arachnoid cyst CT scan and 6 cases of cerebral cava angiography CT scan data. Results Intracranial spatocyst CT features are as follows: 1. Intracranial arachnoid cysts occur in the lateral fissure pool, occipital large pool, hemispheric convex area and cerebellar angle pool; 2. Cysts can be polygons (13/34), similar to round (19/34) and semicircular (2/34), clear edges; Cyst was water-like density, CT value 1.6 ~ 17.0Hu, enhanced scan is not enhanced; 4. Posterior fossa and cerebral hemispheric arachnoid cyst often appear mass effect, and the lateral fissure and convex cyst lesion appear less occupying effect; Local cranial often compressed thinning (22/34); CT scan cisterns immediately, contrast agent is not filled cysts, delayed 1.5 ~ 4.5h scan, see the contrast agent filled cysts, the edge smooth and sharp. Conclusion CT scan is an effective diagnostic and differential diagnosis method for intracranial arachnoid cyst. CT scan of cerebral cava can fully show whether the arachnoid cyst and subarachnoid space are in common and patency, and the choice of neurosurgical treatment plan A guiding role