Centre de Résonance Magnétique Biologique et Médicale (CRMBM), UMR 7339, CNRS, Aix-Marseille Univ, Marseille, France.
Magn Reson Med. 2013 May;69(5):1226-32. doi: 10.1002/mrm.24360. Epub 2012 Jun 12.
MR spectroscopy allows a noninvasive assessment of metabolic information in healthy and pathological central nervous system. Whereas MR spectroscopy has been extensively applied in the brain, only few spectroscopic studies of the spinal cord (SC) have been performed so far. For mice, due to additional technical challenges, in vivo 1H SC MRS has not yet been reported. In this work, the feasibility of short echo time localized proton magnetic resonance spectroscopy using Point RESolved Spectroscopy sequence for the examination of mouse cervical SC at 11.75 T is presented. Several optimizations were performed to improve the static field homogeneity, to reduce physiological motion effects and lipid contaminations arising from SC surrounding tissues, and to provide a careful metabolic quantification. Satisfactory spectrum quality was obtained. The described protocol allowed reliable quantification of five metabolites in the cervical SC. The mean reproducibility regarding the quantification of tNAA, tCr and tCho was ≥80%, >70% for mI and >55% for Glu, whereas the intersubject variabilities were ≤21%. The application of this protocol to transgenic mouse models in pathological conditions such as SC injury or neurodegenerative diseases may thus provide complementary information to MRI and increase our understanding of such pathologies.
磁共振波谱成像可无创评估中枢神经系统的代谢信息。磁共振波谱成像已广泛应用于大脑,而目前仅对脊髓(SC)进行了少量的光谱研究。对于小鼠,由于额外的技术挑战,目前尚未报道在体 1H SC MRS。在这项工作中,介绍了在 11.75T 下使用点分辨波谱序列进行短回波时间局部质子磁共振波谱成像检查小鼠颈段 SC 的可行性。进行了多项优化以提高静磁场均匀性,减少来自 SC 周围组织的生理运动效应和脂质污染,并进行仔细的代谢定量。获得了令人满意的光谱质量。所描述的方案允许可靠地定量颈段 SC 中的五种代谢物。tNAA、tCr 和 tCho 的定量重现性≥80%,mI 的定量重现性>70%,Glu 的定量重现性>55%,而受试者间变异性≤21%。该方案在病理条件下(如 SC 损伤或神经退行性疾病)应用于转基因小鼠模型,可能会为 MRI 提供补充信息,并加深我们对这些病变的理解。