听神经瘤CT、MRI诊断比较

目的：比较听神经瘤的CT、MRI诊断价值。方法：回顾性分析26例经手术和病理证实的听神经瘤的CT、MRI表现。结果：听神经瘤的MRI表现为桥小脑角区圆形或类圆形肿块,于T1WI呈低信号或等信号,T2WI呈高信号或混杂信号;增强扫描显示病灶实质部分及增粗的听神经明显强化,呈“苹果柄”样改变。CT表现为桥小脑角部低密度或等密度病灶,薄扫可见同侧内听道口扩大。结论：CT能直观地显示内听道口的扩大,但常规扫描易漏诊。／MRI多层面成像及无骨伪影的优点,对显示听神经瘤瘤体及病侧听神经增粗很有价值,增强后的“苹果柄”样改变是听神经瘤特征性的表现。

Comparison of CT and MRI in the diagnosis of acoustic neuroma

Objective:To compare valued of CT and MRI in the diagnosis of acoustic neuroma.Methods:To analyze retrospectively CT and MR manifestations of acoustic neuroma of 26 cases proved by surgery and pathology.Results:On MR,acoustic neuroma presented mass lesion.The lesion appeared hypointense or isointense on T 1WI and hyperintense or heterogenerous signal intensity on T 2WI.The parenchymal part of the lesion and the widening acoustic nerve were seen obvious contrast enhance and showed "apple stem shape".On CT,the lesion showed equal or low density in cerebellopontine angle.The ipsilateral opening of internal auditory meatus showed enlargement with thin scaning.Conclusion:On CT,the opening of interal auditory meatus could be displayed with direct manner but easily neglected in common scanning.On MR,the advantages of multiplaner imaging without bone artifact were valuable to the display of acoustic neuroma body and ipsilateral auditery nerve widening.the acoustic neuroma was characterized by the sign of "apple stem"on postcontrast image.