目的 应用64排螺旋CT对听神经 瘤内听道及周围结构进行研究，为临床 提供重要信息，为决定手术方式提供依 据。方法 30例听神经瘤患者术前行颅底 CT薄层扫描观察其患侧内听道形态、内 听道周围乳突气房及颈静脉球等情况。 结果 听神经瘤患侧内听道表现为三种形 态：喇叭口状22例(73.3.0％)，壶腹状6 例(20.0％)，不规则形2例(6.7％)。其中 1例不规则形及3例喇叭口状因内听道口较 大未行磨开内听道后壁，通过直接牵拉切 除内听道肿瘤。19例喇叭口状、6例壶腹 状及1例不规则形行磨开内听道后壁切除 内听道肿瘤。其中3例术前CT提示合并有 颈静脉球高位，术中在磨除内听道后壁时 尽量靠近内听道上嵴，且磨除长度较少， 以防止颈静脉球破裂出血。另有2例术前 CT显示乳突气化良好，乳突气房临近内听 道后壁，术中在磨除内听道后壁时乳突气 房被磨开，并立即进行封闭，术后出现轻 微脑脊液漏。结论 听神经瘤应常规行颅 底CT薄层扫描进行术前评估，有助于临床 决定是否磨开内听道后壁及磨除范围，提 高手术全切除可能，降低对患者的创伤。

Objective 64-slice spiral CT was applied to research internal auditory canal and the surrounding structures. To provide important information for preoperative evaluation of acoustic neuroma and to predjct the operative pmcedures. Methods 30 cases with acoustic neuroma underwent the thin CT scanning of the skull base. To observe the form of internal auditory canal, mastoid air cells and jugular bulbin in acoustic neuroma. Results Internal auditory canal of acoustic neuroma were divided into three forms:trumpet(n:22, 73.3.0％), ampulla(n=6, 20.0％)and irregular(n=2, 6.7%). Due to the large internal auditory canal,the posterior wall of internal auditory canal were not removed and the tumor were directly removed through the drawing in 1 case of irregular and 3 cases of ampulla. The posterior walls of internal auditory canal were removed in 19 cases of trumpet, 6 cases of ampulla and 1 case of irregular.3 cases complicated with high jugular bulb. High speed steel cutting drill was used to drill the posterior walls of internal auditory canal as close as possible to the inner rear wall and as shorter as possible ,to prevent jugular bulb bleeding. 2 cases showed good gasification mastoid. Mastoid air cells were opened during the surgery and were closed immediately, having slight leakage of cerebrospinal fluid after surgery. Conclusion Thin CT scanning of the skull base should be done routinely for preoperative assessment of acoustic neuroma. Because it is helpful to the appropriate management of the posterior wall of internal auditory canal.All of these can improve surgical resection and reduce the trauma to the patient.