质子磁共振波谱对脑肿瘤的鉴别诊断价值

~1H-MR Spectroscopy of Brain Tumors

目的 :初步探讨氢质子磁共振波谱(1H -MRS)对不同脑肿瘤的诊断及鉴别诊断价值。材料和方法 :39例颅内肿瘤分别行常规MRI及 1H -MRS检查 ,将肿瘤实质与对侧相应部位及正常对照组行对照研究。检查方法为PRESS序列 ,主要观察代谢物为氮 -乙酰天门冬氨酸(NAA)、含胆碱的化合物(Cho)、肌酸(Cr/PCr)、乳酸(Lac)和脂类(Lipids)。结果 :几乎所有肿瘤波谱均呈现NAA峰降低 ,Cho升高 ,Cho/Cr及Cho/NAA比值升高 ,与正常组织相比有显著性差异(p<0.05)。低度恶性胶质瘤组8例Cho/Cr、NAA/Cr、NAA/Cho代谢物比值分别为1.87±0.45、1.13±0.26、0.74±0.21 ;高度恶性胶质瘤组7例的代谢物比值的均值分别为2.75±1.17、1.07±0.31和0.62±0.28 ;脑膜瘤组11例 ,其代谢物比值的均值分别为6.04±2.15、0和0 ;转移瘤组10例 ,其代谢物比值的均值分别为2.32±1.08、1.22±0.17和1.23±0.46。胶质瘤组2例术后与术前比较Cho/Cr比值有明显降低。淋巴瘤1例放疗后较放疗前Cho/Cr比值降低 ;听神经鞘瘤1例见升高的Cho峰 ;蛛网膜囊肿1例仅见Lac峰。结论 :H1-MRS对脑肿瘤的诊断及鉴别诊断、治疗后随访、手术后疗效的评价均有重要价值 。

Purpose:To investigate the value of hydrogen-1 magnetic resonance spectroscopy(1H-MRS)in diagnosis and differential diagnosis of intracranial tumors.Materials and Method:Thirty-nine patients with intracranial tumors underwent conventional MRI and single voxel MR spectroscopy both in the lesion's region and the contralateral side.A PRESS acquision was used for 1H-MRS and the metabolites of NAA,Cho,Cr,Lac and Lipids were analyzed.Results:Almost all of the spectrae of these tumors were characterized by reduced N-acetylaspartate,increased signal from Choline-containing compounds,and high ratios of Cho/Cr and Cho/NAA,and significant differences were found between the lesion's region and the contralateral side.Significant differences of Cho/Cr ratio were found between low-grade gliomas and high-grade ones,and so were between gliomas and meningiomas.Cho/Cr ratios of high-grade gliomas were similar to metastatic lesions.The spectra obtained after operation were remarkably different from those before operation.Conclusion:1H-MRS has important value in the differential dignosis,evaluation of operation and following-up of intracranial tumors,and it can also serve as a noninvasive diagnostic method.