质子磁共振波谱对脑肿瘤的鉴别诊断价值

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,可作为一种非损伤性的辅助诊断手段.

1H-MR Spectroscopv of Brain Tumors

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.