囊性脑膜瘤的MRI诊断及分型

Analysis of MRI diagnosis and classification of cystic meningioma

目的:分析囊性脑膜瘤的MRI诊断、分型及其对于手术的指导价值。方法:搜集本院2015年7月-2018年1月收治的20例囊性脑膜瘤患者的临床、MRI及手术资料,采用Rengachary分型、Nauta分型及Worthington提出的NautaⅤ型进行分析及总结。结果:20例患者中最多见的发病部位为大脑凸面(11/20),其中13例为Rengachary瘤内型,7例为Rengachary瘤周型;NautaⅠ型6例,NautaⅡ型7例,NautaⅣ型6例,无NautaⅢ型病例,其中1例为NautaⅤ型;头颅MRI示病灶以不同比例囊实性成份组成,实性成份在T_1上为等或稍低信号,在T_2上呈等或稍高信号,囊性成份在T_1上为低信号,T_2上呈高信号,增强扫描病灶的实性成份明显强化,囊性成份未见强化,囊壁17例强化(Ⅰ型6例,Ⅱ型7例,Ⅳ型3例,Ⅴ型1例),3例无强化(Ⅳ型3例)。手术中均完整的切除了囊壁,术后病理证实囊壁强化的17例中有2例不含肿瘤细胞(Ⅳ型),囊壁无强化的3例中,1例含有肿瘤细胞(Ⅳ型)。术后随访8例,无复发。结论:囊性脑膜瘤少见,术前正确的诊断及MRI分型对手术方案的选择有重要的指导意义。

Objective:To investigate the MRI diagnosis and classification of cystic meningioma using and its guiding value for surgery. Methods:The clinical data,MRI,surgery and pathologic results of 20 patients with cystic meningioma were retrospectively analyzed.The classification of Rengachary,Nauta and Worthington's Nauta Ⅴ were adopted to analyze and summarize. Results:The most common site was the cerebral convexity (11/20).According to the classifications,13 cases were Rengachary intratumoral and 7 cases Rengachary peritumoral,6 cases Nauta Ⅰ,7 cases Nauta Ⅱ,and 6 cases Nauta Ⅳ;no Nauta Ⅲ was in this study,1 case was Nauta Ⅴ.MRI showed the tumors were mixed solid with cystic components in different ratio.The solid parts of the tumors demonstrated slight hypointense or isointense on T 1-weighted images,isointense or slight hyperintense on T2-weighted images,with significant enhancement after gadolinium administration.The cystic component showed hypointense on T 1-weighted images,hyperintense on T 2-weighted images.The cyst wall was enhanced in 17 cases (6 cases Nauta Ⅰ,7 cases Nauta Ⅱ,3 cases Nauta Ⅳ,1 case Nauta Ⅴ);there was not enhanced in 3 cases (Nauta Ⅳ).All tumors with cyst wall were completely resected by surgery.There was not tumor cells found in 2 cases (Nauta Ⅳ).One tumor contained tumor cells in the 3 cases without cyst wall enhancement (Nauta Ⅳ).8 cases were followed up and no recurrence was found. Conclusion:Cystic meningiomas are rarely found and prone to misdiagnosis.Correct diagnosis and classification before surgery have important guiding significance for the selection of surgical approaches.