颅内胆脂瘤高场强MRI分析

MRI analysis of intracranial cholesteatoma

目的：颅内胆脂瘤高场强ＭＲＩ在颅内胆脂瘤检查中扫描序列的选择，压脂技术（ＦＳ）和３ＤＳＰＧＲ技术的应用，进一步认识颅内胆脂瘤的信号特征。方法：收集８例临床资料完整，手术、病理证实的颅内胆脂瘤病例，常规采用自旋回波（ＳＥ）序列，部分加反转恢复脂肪抑制技术，常规增强，应用３ＤＳＰＧＲ技术，Ｓａｇ、Ｃｏｒ、Ａｘｌ重建成像。结果：肿瘤部分以桥小脑角区（ｃｐａ）最多（５例），中、后颅窝共３例，形态呈不规则形（５例），类圆形（３例），边界清楚，大部分光整，均无灶周水肿。信号特征为长Ｔ１、短Ｔ２（２例），且多数不均匀。压脂后扫描见信号明显由高变低，增强后大多完全不强化，仅少数可强化。结论：高场强ＭＲＩ在胆脂瘤检查中的脂肪抑制技术及３ＤＳＰＧＲ技术应用，能够清晰地显示胆脂瘤的结构信号特征，与其它肿瘤相鉴别，作出准确的术前诊断。

Purpose:To assess the choice of scanning sequence and the application of FS and 3D SPGR technique in MRI of cholesteatoma,to improve the recognition of the characteristic signals and master the diagnosis and differential diangnasis of cholesteatoma.Methods:8 surgical confirmed cases with complete clinical data were collected.All contrast enhanced MR image had spine echo (SE),inversion recovery fat suppression IRFSE,3D SPGR was performed partly.Results:Cholesteatoma was located in cerebello pontine angle (CPA) (5 cases),mediacranial fossae (1 case),postcranial fossae (2 cases).The shape of the masses were irregular (5 cases),oval (3 cases). All were regular and well demarcated without perifocal edema,MR image signal patterns were long T 1,long T 2(6 cases). Short T 1 short T 2 (2 cases) and mostly with inhomogenous density.There was no enhancement following contrast media injection in most cases,and hyperintense signal turned to hypointensity after using FS.Conclusion:FS and 3D SPGR sequence in MRI of cholesteatoma present specific signals and constructive patterns.Therefore differential diagnosis and accurate qualitative diagnosis can be drawn before operation.