非典型脑膜瘤的MRI诊断

MRI diagnosis of atypical meningioma

目的:分析非典型脑膜瘤的MRI表现及病理基础,以提高对该肿瘤的认识。方法:回顾性分析经手术病理证实的15例非典型脑膜瘤的MRI表现,探讨肿瘤的部位、形态、有无出血囊变、瘤体占位效应、瘤周水肿、瘤体信号及强化特点,并行病理对照分析。结果:本组15例非典型脑膜瘤,部位典型者13例(86.7%),典型部位以大脑镰、矢状窦旁、大脑凸面、鞍旁、桥小脑角区为主;非典型者2例(13.3%),其中眼眶1例(6.7%),侧脑室1例(6.7%)。MRI扫描,肿瘤类圆形12例(80%),不规则形2例(13.3%),分叶状1例(6.7%)。瘤内出血3例(20%),囊变4例(26.7%)。瘤周水肿12例(80%)。瘤体占位效应者13例(86.7%)。平扫信号均匀者3例(20%),不均匀12例(80%)。瘤体DWI呈等信号者10例(66.7%),高信号3例(20%),高低混杂信号2例(13.3%)。强化均匀者3例(20%),不均匀12例(80%)。术后复发3例(20%)。结论:非典型脑膜瘤的MRI表现有一定特征性,根据肿瘤的部位、信号及强化等特点,结合患者的临床发病特点,可提高对该肿瘤的术前诊断。

Objective：To evaluate the MRI characteristics and pathological basis of atypical meningioma for the aim of improving the diagnosis of the tumor.Methods：MRI data of fifteen patients with atypical meningioma proved by surgery and pathology were retrospectively analyzed,and the features including the location,form,hemorrhage,cystis degeneration,edema,signal intensity and contrast enhancement were observed in correlation with the pathology.Results：Of 15 cases,13 were located in typical places（86.7%）,mainly at the cerebral falx,sagittal sinus,convexity of brain,parasellar,and cerebellopontine angle,2 were in atypical location（13.3%）,mainly in orbit and lateral ventricle.On the MRI,12 cases showed heterogeneous intensity（80%）,2 had irregular shape（13.3%）,1 had lobular form（6.7%）;3 had hemorrhage（20%）,4 had cystis degeneration（26.7%）;12 had edema（80%）;3 cases had homogeneous signal（20%）,12 had inhomogeneous signal（80%）;On DWI,the tumor showed isointensily in 10 cases（66.7%）,hyperintensity in 3 cases（20%）,and mixed signal intensity in 2 cases（13.3%）.3 cases had relapse（20%）.Conclusion：MRI features of atypical meningioma were characteristic to some extent according to the tumor′s signal and enhancement,which,with reference to the patient′s clinical history,can help us to improve the diagnosis of the tumor.