应用多体素磁共振波谱成像鉴别脑胶质瘤与单发脑转移瘤

The application of multi-voxel magnetic resonance spectroscopy in differentiating gliomas from solitary intracranial metastases

目的:探讨磁共振氢质子波谱成像对低级别胶质瘤、高级别胶质瘤及转移瘤中的鉴别作用。方法:回顾性分析经病理或临床证实脑肿瘤疾患27例,包括19例脑胶质瘤、8例脑单发转移瘤。根据WHO2007年分类标准,将胶质瘤分为低级别胶质瘤(Ⅰ-Ⅱ级)7例,高级别(Ⅲ-Ⅳ级)胶质瘤12例。应用GE ADW4.2后处理工作站,获得肿瘤实质中心区、肿瘤边缘、瘤周水肿区、对侧(或远离病灶)正常脑白质的各代谢物谱线及乙酰天门冬氨酸/胆碱复合物(NAA/Cho)比值,并按低级别胶质瘤组、高级别胶质瘤组及脑转移瘤组进行分析。结果:(1)MRS谱线形态,所有病例肿瘤实质中心区较正常对照均表现为NAA、Cr峰下降,Cho峰升高;5例高级别胶质瘤出现Lip峰,4例转移瘤出现Lip峰。(2)所有病例肿瘤实质中心区、肿瘤边缘、瘤周水肿区NAA/Cho比值较正常对照下降(P<0.05);高级别胶质瘤肿瘤实质中心区与肿瘤边缘、肿瘤实质中心区与瘤周水肿间NAA/Cho比值的差异均有统计学意义(P<0.05),肿瘤边缘与瘤周水肿区NAA/Cho比值的差异无统计学意义(P>0.05);转移瘤肿瘤实质中心区、肿瘤边缘、瘤周水肿区两两NAA/Cho比值的差异均有统计学意义(P<0.05);低级别胶质瘤与高级别胶质瘤间、高级别胶质瘤与转移瘤间肿瘤实质中心区、肿瘤边缘、瘤周水肿区的NAA/Cho比值的差异均有统计学意义(P<0.05)。结论:低级别胶质瘤、高级别胶质瘤、脑转移瘤的肿瘤实质中心区均表现为NAA、Cr峰下降,Cho峰升高;Lip出现与否、NAA/Cho比值有助于提高低级别胶质瘤、高级别胶质瘤、脑转移瘤的影像诊断的准确率。

Aim：To evaluate the differential value of multi-voxel proton magnetic resonance spectroscopy among low-grade gliomas,high-grade gliomas and metastases. Methods： Twenty-seven cases of intracranial tumors proved pathologically or by primary tumor history were analyzed retrospectively,including 7 cases of low-grade gliomas,12 cases of high-grade gliomas and 8 case of solitary metastases.The metabolite ratio of NAA/Cho were assessed from spectral maps in the tumoral parenchymal core,tumoral edge,peritumoral edema and contralateral normal tissue.The differences among low-grade gliomas,high-grade gliomas and solitary metastases were analyzed statistically. Results： The ratios of NAA/Cho of tumoral parenchymal core of brain tumors were decreased compared with normal tissue.There were significant differences in the tumoral parenchymal core or tumoral edge or peritumoral edema between low-grade gliomas and high-grade gliomas,so were between high-grade gliomas and solitary metastases（P〈0.05）.In high-grade gliomas,tumoral parenchymal core and tumoral edge differed significantly,so did tumoral parenchymal core and peritumoral edema（P〈0.05）.The ratios of NAA to Cho had significant differences between different locations in the metastases（P〈0.05）. Conclusion：The presence of lipid and the ratio of NAA to Cho were potential in the distinction of low-grade gliomas,high-grade gliomas and metastases.