~1H-MRS在脑胶质瘤诊断及分级中的应用

目的:分析脑胶质瘤的氢质子磁共振波谱(proton magnetic resonance spectroscopy,1H-MRS)表现及其临床意义;探讨脑胶质瘤的1H-MRS特点与其病理级别相关性。方法:搜集经临床手术、病理证实的脑胶质瘤38例,按照WHO分级(2000)标准分成两组:低级别脑胶质瘤组、高级别脑胶质瘤组。所有患者在术前行1H-MRS检查,均在MR非增强成像的基础上获得。使用GE Signa1.5T超导磁共振扫描仪,多体素扫描,点分辨选择波谱法,检测不同区域代谢物变化。结果:脑胶质瘤的1H-MRS表现:肌酸(Cr)无明显变化;N-乙酰天门冬氨酸(NAA)下降,胆碱(Cho)增高,变化的程度由肿瘤级别高低决定;低级别、高级别脑胶质瘤的肿瘤组织分别和对侧正常脑组织的NAA/Cr、Cho/Cr、NAA/Cho比值存在显著性差异(P<0.01);低级别脑胶质瘤和高级别脑胶质瘤的肿瘤组织的NAA/Cr、Cho/Cr、NAA/Cho比值有统计学意义(P<0.05),脑胶质瘤的NAA/Cho、Cho/Cr、NAA/Cr比值与病理级别相关。结论:1H-MRS与MRI相结合能提高脑胶质瘤术前诊断的准确性。1H-MRS可评价脑胶质瘤的分级,反映脑胶质瘤代谢特性以及肿瘤生长潜能。

Application of 1H-MRS in diagnosis and pathological grading of brain gliomas

Objective: To evaluate the findings and clinical significance of 1H-MRS,and to explore the correlation between the findings of 1H-MRS and the pathological grading of gliomas.Methods: Thirty-eight patients of gliomas approved by pathology were reviewed,all cases were categorized into two groups(low grade gliomas and high grade gliomas) according to WHO diagnostic criteria.The 38 patients underwent 1H-MRS before surgery on plain MRI scanning.Multiple voxel proton magnetic resonance spectroscopy was performed on a 1.5T MR scanner using point resolved selective spectroscopy(PRESS),the variety of metabolite peaks were detected in different areas.Results: The Cr peak of the gliomas was normal,while the NAA peak decreased and the Cho peak increased.Significant differences between low/high grade gliomas and normal tissue in contralateral brain hemispheres were found in the ratios of NAA/Cr,Cho/Cr and NAA/Cho(P<0.01).Statistic differences between low grade gliomas and high grade gliomas were found in the ratios of NAA/Cr,Cho/Cr and NAA/Cho(P<0.05).There was significant correlation between the ratios of NAA/Cr,Cho/Cr and NAA/Cho and the pathological grading of gliomas.Conclusion: The combination of 1H-MRS and MRI improves preoperative diagnostic accuracy of gliomas,1H-MRS has made it possible to evaluate the grade of gliomas,obtain metabolic information of gliomas and reflect the potential growth of tumor.