听神经瘤CT与MRI诊断比较

Comparative assessment of CT and MRI diagnosis of acoustic neuromas

目的：①回顾性分析经ＣＴ和ＭＲＩ检查、手术及病理证实的听神经瘤表现；②比较二者的敏感性和定性诊断效果；③探讨微听神经瘤的检出方法．方法：１９（男９，女１０）例听神经瘤，ＣＴ平扫后１５例增强扫描．ＭＲＩ检查用ＳＥ序列，平扫及增强扫描．结果：ＣＴ正确诊断１５／１９例，漏诊４／１９例．ＭＲＩ检出率为１９／１９例，并可检出５ｍｍ的微听神经瘤．结论：ＣＴ漏诊率为２１％，分析其原因是没有采用ＣＴ薄层及增强扫描，忽略了内听道骨窗观察．ＭＲＩ薄层及增强技术是检出听神经瘤的最佳方法，且可观察三叉神经脑池段有无受侵．

Aim: ①To analyze retrospectively the diagnosis of acoustic neuroma by CT and MRI and confirmed by pathology;②To evaluate the sensitivity and qualitative diagnosis of CT and MRI;③To discuss the examination parameters of acoustic micro neuromas. Methods: Nineteen cases of acoustic neuromas including 9 men and 10 women were examined by plain CT scannings and 15 post contrast examinations. Results: 15/19 cases of CT scans were correct and 4/19 cases were not. 19 cases of MRI examination were positive including 1 case of 5 mm micro neuroma. Conclusion: The reason of 21% CT misdiagnosis was abscence of thin slice enhancement and neglect of investigating the internal auditary meatus. Combining thin slice and Gd DTPA in MRI examination was the best method to find acoustic neuromas and to detect whether the V nerve in the subrachnoid segment was invaded or not.