MR扩散加权成像ADC值联合增强扫描在血管瘤型脑膜瘤的术前诊断价值

Value of MR Diffusion-Weighted Imaging Combined with Enhanced Scan in Preoperative Diagnosis of Angiomatous Meningioma

目的探讨MR扩散加权成像ADC值联合增强扫描在血管瘤型脑膜瘤的术前诊断价值。方法回顾性分析21例经手术病理证实的血管瘤型脑膜瘤的常规MRI平扫+增强表现、DWI表现及病理特征,测量肿瘤ADC值与对侧脑实质ADC值,并进行分析;并将血管瘤型脑膜瘤与其他病理亚型脑膜瘤ADC值进行对比分析。结果21例血管瘤型脑膜瘤中有15例行MRI平扫,21例均行MRI增强。21例中有15例位于大脑凸面,2例位于颅底,1例位于桥小脑角区,3例位于鞍旁。常规MRI平扫表现13例肿瘤呈长T1、长T2信号,2例肿瘤呈等T1、等T2信号;DWI上4例肿瘤呈稍高信号,8例肿瘤呈高信号,3例肿瘤呈等信号;15例肿瘤表现明显瘤周水肿,6例瘤周无明显水肿;增强扫描所有肿瘤均表现出明显强化,强化方式呈不均匀强化。其中14例肿瘤有脑膜尾征;15例肿瘤内部及周围可见流空血管影;3例肿瘤表现明显囊变、坏死,并可见液液平。血管瘤型脑膜瘤平均ADC值大于对侧脑实质平均ADC值,差异有统计学意义(P<0.01);血管瘤型脑膜瘤平均ADC值大于其他病理亚型脑膜瘤平均ADC值,差异有统计学意义(P<0.01)。病理切片21例血管瘤型脑膜瘤均见成熟血管成分,7例行免疫组织化学,肿瘤细胞波形蛋白(Vim)均为阳性,6例上皮膜抗原(EMA)阳性,1例弱阳性。结论血管瘤型脑膜瘤ADC值较对侧脑实质增高,并高于其他病理亚型脑膜瘤,有助于诊断该型肿瘤,联合MR增强特征表现在术前诊断中有重要价值。

Objective To evaluate the value of MR diffusion weighted imaging combined with enhanced scan in preoperative diagnosis of angiomatous meningioma.Methods The conventional MRI findings,DWI findings and pathological features of 21 cases of angiomatous meningiomas confirmed by surgery and pathology were retrospectively analyzed.The ADC values of the tumors and the parenchyma of the contralateral brain were evaluated and analyzed.The ADC values of angiomatous meningiomas and other pathological subtypes of meningiomas were compared and analyzed.Results Of the 21 cases of angiomatous meningiomas,15 cases were examined by MRI plain scan,21 cases were examined by enhanced MRI,15 cases were located on the convex surface of the brain,2 cases were located at the base of the skull,1 case was located in the cerebellopontine angle region,and 3 cases were located in the paasellar region in the 21 cases of angiomatous meningioma.Conventional MRI showed long T1 and long T2 signal intensity in 13 cases,isointense T1W signal in 2 cases,slightly hyperintense DWI signal in 4 cases,hyperintense signal in 8 cases,isointense signal intensity in 3 cases,hyperintense signal intensity in 8 cases and isointense signal intensity in 3 cases.The tumor showed obvious peritumoral edema in 15 cases and no obvious edema in 6 cases.All the tumors showed obvious enhancement after gadolinium administration,and the enhancement pattern was uneven.Among them,14 cases had dural tail sign,15 cases showed flow void vessels in and around the tumor,and 3 cases showed obvious cystic change,necrosis and fluid-fluid level.The mean ADC value of angio-matous meningioma was higher than that of contralateral brain parenchyma(P<0.01).The mean ADC value of angiomatous meningiomas was higher than that of other pathological subtypes of meningiomas(P<0.01).Mature vascular components were found in 21 cases of angiomatous meningioma,immunohistochemical staining was performed in 7 cases,vimentin(Vim)of tumor cells was positive in all cases,and 6 cases were positive for vimentin.The skin membrane antigen(EMA)was positive,and one case was weakly positive.Conclusion The ADC value of angiomatous meningioma is higher than that of contralateral brain parenchyma and higher than that of other pathological subtypes of meningioma,which is helpful for the diagnosis of this type of tumor.Combined with MR enhancement features,it has important value in preoperative diagnosis.