多元质子磁共振质子波谱诊断脑肿瘤

目的 :分析 2D磁共振质子波谱 (MRS)和肿瘤手术切除病理的关系 ,探讨 2DMRS在脑肿瘤诊断中的作用。方法 :34例磁共振成像 (MRI)疑为脑肿瘤患者进一步行MRS检查。所有肿瘤均经手术后病理或立体定向组织活检证实。测量 2 .0、3.0及 3.2ppm处的N 乙酰门冬氨基酸盐 (NAA)、肌酐 (Cr)、胆碱 (Cho)峰下面积 ,计算正常脑实质、肿瘤、瘤周NAA/Cr、Cho/Cr、NAA/Cho。　结果 :以对侧正常脑组织作参照组 ,和对侧正常脑组织MRS比较 ,胶质瘤NAA/Cr、NAA/Cho值明显降低 (P <0 .0 5 ,P <0 .0 1) ,Cho/Cr值升高 (P <0 .0 5 ) ,而NAA/Cho值较瘤周水肿区明显下降 (P <0 .0 5 )。脑膜瘤的NAA/Cr值降低 ,但和正常区无显著差异 ,而Cho/Cr值升高 (P <0 .0 5 ) ,NAA/Cho下降 (P <0 .0 1)。尽管瘤体NAA/Cr值低于瘤周 ,但无显著统计学意义 ,而瘤周Cho/Cr值明显低于瘤内 ,NAA/Cho值高于瘤内 (P <0 .0 5 )。胶质瘤和脑膜瘤NAA/Cr和Cho/Cr无鉴别诊断意义 ,但是胶质瘤NAA/Cho值下降比脑膜瘤更明显 (P <0 .0 5 ) ;脑膜瘤和胶质瘤的瘤周NAA/Cr值无显著差异 (P >0 .0 5 ) ,而Cho/Cr值、NAA/Cho值有显著差异 (P <0 .0 5 )。　结论 :多元1H MRS检查弥漫性或不均匀脑肿瘤更具优越性 ,对脑肿瘤的诊断、鉴别诊断有重要的临床价值

Diagnosis of brain tumors with multiple-voxel proton MR spectroscopy

Objectives:To investigate the value of two dimensional proton MRS in diagnosis of intra cranial tumors on bases of correlation with histopathologic analysis of resection specimens. Methods:Thirty four patients with MRI diagnosis of brain neoplasms further underwent MR spectroscopy examination. The final diagnosis was verified by surgical histopathology or stereo surgical biopsy. MRS imaging was performed at 1.5T with the multiple voxel point resolved spectroscopy pulse sequence.NAA, creatine and choline peak areas were estimated by integrating the resonance at 2.0,3.0 and 3.2 ppm respectively. NAA/Cr ratio, Cho/Cr ratio and NAA/Cho ratio in the normal brain, tumors and area around tumors were calculated statistically. Results: In 18 patients with glioma, the NAA/Cr and NAA/Cho decreased significantly while Cho/Cr increased significantly in comparison of glioma with contralateral normal brain. NAA/Cho was significantly lower than the edema area around glioma. In 10 patients with meningoma,there was no significant difference in decreased NAA/Cr, but significant difference in increased Cho/Cr and decreased NAA/Cho between meningoma and the normal value. This study also showed Cho/Cr and NAA/Cho but NAA/Cr had statistical difference between the area around meningoma and meningoma, It was impossible for decreased NAA/Cr and increased Cho/Cr to differentiate glioma from meningoma, but NAA/Cho of glioma was significantly lower than that of meningoma.Proton MRS around of meningoma showed significant difference in Cho/Cr and NAA/Cho and no significant difference in NAA/Cr in comparison with glioma. Conclusions:This study demonstrated that 2D proton MRS imaging toon an advantage in diffuse or heterogeneous tumors due to its more extended examination area, which may be a valuable modality in diagnosis and differential diagnosis of brain tumors.