磁共振波谱评价大脑半球代谢物的偏侧优势

EVALUATION OF LATERALIZATION OF METABOLITES IN BILATERAL CEREBRAL HEMISPHERE REVEALED BY THE PROTON MRS

为了利用无创性的磁共振波谱成像技术研究大脑半球代谢物的非对称性,本研究对56例正常成年人行磁共振波谱成像,主要对双侧大脑半球的4个解剖区域:额叶、颞叶、枕叶及顶叶的代谢物天门冬氨酸(NAA)、肌酸(Cr)、胆碱(Cho)进行测量,并以Cr为内参照物比较NAA和Cho相对含量(NAA/Cr、Cho/Cr)的侧别差异。结果表明:双侧额叶之间的NAA/Cr存在显著性差异,而Cho/Cr无显著性差异;在双侧颞叶之间,这2种比值均存在显著性差异;双侧枕叶之间Cho/Cr存在显著性差异,而NAA/Cr无显著性差异;双侧顶叶之间的NAA/Cr存在显著性差异,而Cho/Cr无显著性差异。本研究结果提示双侧大脑半球的代谢物存在偏侧优势。

In order to study the biochemical asymmetry in normal human brain by using the non-invasive technique of the proton magnetic resonance spectroscopy （ ^1H-MRS） , 56 healthy right-handed subjects were selected to acquire water-suppressed proton spectra in bilaterally symmetrical positions in the cerebral hemisphere. Four different regions in the frontal, temporal, occipital and parietal cortex, respectively, were examined. The metabolites studied were N-aeetyl aspartate （NAA）, ereatine （Cr） and choline （Cho） containing compounds. Cr was used as a self consultant. The ratios of the NAA/Cr and Cho/Cr in the corresponding peak areas between the symmetrical sites of the right and left cerebral eortexes were calculated and compared. The results showed that in the frontal and parietal cortexes, there were statistically significant differences between the ratios of NAA/Cr, but not the Cho/Cr; in the temporal cortex, there were statistically significant differences between the ratios of both NAA/Cr and Cho/Cr; in the occipital cortex, there were statistically significant differences between the ratios of Cho/Cr, but not the NAA/Cr. The present results suggest that biochemical lateralization is possibly existed in the human brain as being elucidated by the ^1H-MRS.