囊性脑膜瘤的MRI特征分析(附17例)

摘要

目的:分析囊性脑膜瘤的磁共振成像特点,加深对该病的认识,以提高诊断准确率.方法:回顾分析经手术病理证实的17例囊性脑膜瘤,其中男8例,女9例,年龄36~70岁,平均49.7岁,行颅脑MRI平扫和增强,其中3例加做MRS,结合手术病理,采用Nauta分型分析囊性脑膜瘤的MRI表现及特点.结果:囊性脑膜瘤主要位于大脑凸面,以广基与硬脑膜相连,MRI多表现为实性肿物伴有大小不等的囊变区,实性部分以等或长T1长T2信号为主,囊性部分均表现为长T1长T2信号;增强扫描实性部分呈中度或明显强化,囊壁可有或无强化.本组17例中,Nauta I型7例,NautaⅡ型8例,NautaⅣ型2例.结论:囊性脑膜瘤较为少见且不易于与其他颅内囊室性病变进行鉴别,磁共振常规扫描结合增强扫描及MRS有助于对该疾病正确诊断,同时对临床治疗和手术方案设计有一定的指导意义.%Objective:To analyse the magnetic resonance imaging features of cystic meningiomas,to help avoid misdiagnosis and improve the diagnostic accuracy.Methods:Retrospectively evaluated the data of 17 patients with cystic meningiomas.There were 8 males and 9 females,and the age ranged from 36~70 years old with the average age of 49.7 years old.17 patients had unenhanced MRI or enhanced MRI.And 3 patients underwent magnetic resonance spectroscopy(MRS).We adopted Nauta''s classification and reviewed the literature with respect to their MR imaging features and histopathology results.Results:Cystic meningiomas were frequently located on the cerebral convexity,connected to the dura with broad base.MRI scans showed the tumors solid and mixed cystic lesions.The solid parts of the tumors demonstrated hypointense or isointense on T1-weighted images,isointense or hyperintense on T2-weighted images,with significant enhancement after gadolinium administration.The cystic wall showed enhancement or not.MRS showed the absence of N-Acetyl Aspartate,a prominent choline peak with a shallow creatine peak.Of the 17 cases,seven cases were Nauta I,eight cases were NautaⅡ,and two cases were NautaⅣ.Conclusion:Cystic meningiomas were particularly uncommon tumors that are often difficult to distinguish from other intra-axial solid and mixed cystic lesions.Conventional MRI and MRS could play a significant role in the diagnosis of cystic meningiomas,the preoperative clinical treatment and proper surgical program.