Gd-DTPA对胶质瘤磁共振波谱分析的影响研究

目的 探讨对比剂Gd-DTPA对颅脑胶质瘤氢质子磁共振波谱的影响.方法 28例脑胶质瘤患者（Ⅲ级间变型星形细胞瘤13例、Ⅳ级胶质母细胞瘤15例）,先行MRI平扫,包括T1WI轴位和矢状位扫描、T2WI轴位扫描、T2WI轴位FLAIR扫描.在FLAIR序列上选取肿瘤最大层面,设置感兴趣区进行三位多体素或者单体素氢质子波谱扫描.经肘静脉团注15 ml磁共振对比剂Gd-DTPA后行增强扫描,在肿瘤强化明显后再次行1H-MRS,位置及扫描参数与平扫 MRS完全一致.采用Philips波谱分析软件,比较注射对比剂前后胶质瘤强化区代谢产物NAA、Cr、Cho、NAA/Cr、ChdCr、NAA/Cho值.结果 胶质瘤平扫与增强MRS的瘤体强化区代谢产物NAA、Cr、Cho、NAA/Cr、Cho/Cr、NAA/Cho值分别为（0.20±0.08、0.19±0.09）、（0.24±0.15、0.23±0.15）、（0.51±0.16、0.53±0.17）、（1.02±0.69、0.99±0.63）、（2.76±1.46、2.79±1.51）、（0.41±0.20、0.38±0.17）,差异无显著性（P〉0.05）.结论 Gd-DTPA对波谱图像无影响,1H-MRS宜在增强扫描后进行,更准确地反映病变区域的代谢物情况.

Impact of Gd-DTPA on magnetic resonance spectroscopy analysis of glioma

Objective To explore the impact of Gd-DTPA, a contrast agent, on proton magnetic resonance spectroscopy analysis of glioma. Methods MRI scans were performed in 28 patients with glioma ( 13 Ⅲ grade anaplastic astrocytoma and15 Ⅳ grade glioblastoma), includingT1WI axial and sagittal scans,T2WI axial, T2WI axial FLAIR scans. The maximum levels of tumors in the FLAIR sequence were selected as views of interest for three dimension multi-or single-voxel proton spectroscopy scanning. After injection of 15ml of Gd-DTPA, enhanced MRI scans were performed and the level of marked enhancement in tumors were selected. 1H-MRS were performed again, consistent with the plain MRS scans in location and scanning parameters. Philips spectral analysis software was used to compare the values of NAA, Cr, Cho, NAA/Cr,Cho/Cr, and NAA/Cho before and after injertion of contrast agent in enhancement area glioma. Results The values of NAA, Cr, Cho, NAA/Cr, Cho/Cr, and NAA/Cho in plain and enhanced glioma MRS in the lesion enhancement area were ( 0.20 ± 0.08, 0.19 ± 0.09 ), ( 0.24 ± 015, 0.23 ± 0.15 ), ( 0.51 ±0.16, 0.53 ± 0.17 ), ( 1.02 ± 0.69, 0.99 ± 0.63 ), ( 2.76 ± 1.46, 2.79 ± 1.51 ), and ( 0.41 ± 0.20,0.38 ± 0.17 ); with no significant differences ( P> 0.05 ). Conclusion Gd-DTPA has no effect on the quality of spectral images. 1H-MRS should be performed after enhanced scans, which can more accurately reflect the metabolic activity of the lesions.