血管瘤型脑膜瘤的MRI特点及手术治疗

MRI features and surgical strategy of angiomatous meningiomas

目的 探讨血管瘤型脑膜瘤的MRI特点及手术策略。方法 回顾性分析经手术后病理证实的51例中枢神经系统血管瘤型脑膜瘤及50例其他亚型脑膜瘤的MRI特点及临床资料,并进行统计分析.结果 51例血管瘤型脑膜瘤均为单发,其中凸面部31例,蝶骨嵴8例,岩斜部5例,小脑幕3例,鞍区2例,小脑脑桥角区2例.肿瘤最大径1.5 ～6.2cm,平均3.7cm;42例呈椭圆形或类圆形,3例可见分叶,6例呈不规则状;38例以宽基底与硬脑膜相连;39例可见脑膜尾征;46例瘤组织中可见血管流空信号;4例出现囊变、坏死.MRI平扫T1WI多呈低信号,T2WI呈高信号,增强后呈显著均匀强化,少数肿瘤囊变部分增强后未见强化.除脑膜尾征之外,在肿瘤大小、钙化率、瘤周水肿、水肿指数（EI）、血管流空信号等方面的差异均有统计学意义（P＜0.05）.51例均行手术治疗,其中Simpson Ⅰ级切除38例,Ⅱ级切除9例,Ⅲ～Ⅳ级切除4例,无死亡病例.术后随访2个月～3年,肿瘤复发2例。结论 血管瘤型脑膜瘤的MRI表现具有一定的特点,即TIWI多呈均匀的低信号,T2WI呈均匀的高信号,常伴有范围较大的瘤周水肿,血管流空信号多见.可与其他类型脑膜瘤及恶性肿瘤相鉴别.术前结合DSA造影,选择合理的手术入路是手术成功的关键。

Objective To analyze the MRI features and surgical strategy of angiomatous meningioma （AM）.Methods The MRI findings and pathological data of 51 cases with AM and 50 cases with other subtypes of meningiomas were retrospectively analyzed.Two groups of cases had been confirmed by surgery and pathology.Results Thirty-one tumors were found beside convexity,8 in sphenoidal crest,5 in petroclival region,3 in tentorium of cerebellum,2 in saddle area,and 2 in cerebellopontine angle area.The max diameter of AM ranged from 1.5 cm to 6.2 cm （3.7 cm in average）.42 tumors showed the shape of oval or similar to the oval,3 nodular lobulated and 6 irregular shape.38 tumors showed a broad-based attachment with meninges and 39 displayed dural tail sign.The signal voids of vessels were found in 46 tumors.Only 4 cases of cystic change and necrosis were found.The homogeneous hypointense on T1WI and hyperintense on T2WI were found.The striking enhancement was showed,except several cystic changed ones.The periturnoral brain edema （PTBE） was appeared in 42 tumors.The meningeal tail sign,tumor diameter,calcification rate,PTBE,edema index （EI） and signal voids of vessels of AMs were compared with those of other subtypes of meningiomas.The differences were statistically significant except the first item （P 〈0.05）.38 cases achieved Simpson gradeItumor excision,9 gradeⅡ,and 4 grade Ⅲ-Ⅳ excision.There was no patient death.All patients were followed-up for 2 month to 3 years.There were 2 cases of recurrence.Conclusions The MRI findings of AMs had the certain characteristics of homogeneous hypointense on T1WI and homogeneous hyperintense on T2WI.AMs often had wide PTBE and the signal voids of vessels were common.It＇s characteristics might be helpful in differential diagnosis with other subtypes of meningiomas and malignant tumors.A reasonable surgical approach combined with DSA before the operation was the key to the success of surgery.