fMRI在脑肿瘤诊断中的应用价值初探

目的：探讨fMRI在脑肿瘤诊断、鉴别诊断及肿瘤浸润边界划定中的价值。方法：脑肿瘤35例，均行MR平扫、增强、DWI及MRS。在肿瘤强化区、瘤周区、正常参照区，DWI测量各区域信号值，计算相对表观扩散系数（rADC）值；^1H—MRS行MVS采集NAA、Cho、Cr、Lac等波峰，计算不同区域各代谢物比值均值，比较统计学差异。结果：DWI示肿瘤强化区rADC值在脑膜瘤与星形细胞瘤、转移瘤间有显著性差异（P〈0．05）；瘤周区rADC值在星形细胞瘤与脑膜瘤、转移瘤间有统计学差异（P〈0．05）。多体素^1H—MRS示肿瘤强化区各代谢物比值均值与正常参照区比较有显著性差异（P〈0．05）；瘤周区，星形细胞瘤、转移瘤和脑膜瘤间多组代谢物比值具统计学差异（P〈0．05）。结论：fMRI与常规MRI相结合有助于脑肿瘤的鉴别诊断以及确定病灶浸润范围。

Functional magnetic resonance imaging in the evaluation of brain tumors

Objective To investigate the evaluation of functional magnetic resonance imaging(fMRI) on diagnosis,differentiation and deciding the border of brain tumors.Methods Thirty-five intracranial tumor patients were recruited in this study.All the patients had undergone MR routine scanning,DWI and ~(1)H-MRS.The single values were calculated on enhancement areas of tumors,perienhancement regions and normal white matter.The difference of the mean relative ADCs were made by analysis of variance.Multivoxel ~(1)H-MRS was performed orderly.Spectra of three vowels were taken from the above different areas.Fitted areas in the spectrum for NAA,Cho,Cr,lac and other metabolite peaks were measured.Then the metabolite ratios were calculated for each voxel.Results The mean rADCs from enhancement areas of brain tumors were obtained significantly different between meningiomas and astrocytomas or metastases(P<(0.05)).The rADC values of perienhancement for astrocytemas,metastases and meningiomas were statistically significant(P<0.05).In multivoxel ~(1)H-MRS from the enhancement of the lesion,the metabolite ratios changed significantly by comparing with that of normal control brain tissues(P<0.05).In voxel from perienhancement region,the mean metabolite ratios revealed strong correlations among metabolite concentrations,tumor types(P<0.05).Conclusion fMRI with routine MRI will be useful in differentiation of tumors and deciding the border of tumors.