Carlier P G, Bertoldi D, Baligand C, Wary C, Fromes Y
NMR Laboratory, AFM and CEA, Pitié-Salpêtrière University Hospital, 75013 Paris, France.
NMR Biomed. 2006 Nov;19(7):954-67. doi: 10.1002/nbm.1081.
Tissue perfusion and oxygenation in many organs can be evaluated by various NMR techniques. This review focuses on the specificities, limitations and adaptations of the NMR tools available to investigate perfusion and oxygenation in the skeletal muscle of humans and animal models. A description of how they may be used simultaneously is provided as well. 1H NMR spectroscopy of myoglobin (Mb) monitors intramyocytic oxygenation. It measures the level of deoxy-Mb, from which Mb concentration, Mb desaturation/resaturation rates, muscle oxygenation changes and intracellular partial oxygen pressure (pO2) can be calculated. Positive and negative blood oxygen level-dependent (BOLD) contrasts exist in skeletal muscle. BOLD contrasts primarily reflect changes in capillary-venous oxygenation, but are also directly or indirectly dependent on muscle blood volume, perfusion, vascular network architecture and angulation, relative to the main magnetic field. Arterial spin labelling (ASL) techniques, having high spatial and temporal resolution, are the methods of choice to quantify and map skeletal muscle perfusion non-invasively. Limitations of ASL are poor contrast-to-noise ratio and sensitivity to movement; however, with the introduction of specific adaptations, it has been proven possible to measure skeletal muscle perfusion at both rest and during exercise. The possibility of combining these NMR measurements with others into a single dynamic protocol is most interesting. The 'multiparametric functional (mpf) NMR' concept can be extended to include the evaluation of muscle energy metabolism simultaneously with 31P NMR or with lactate double quantum filtered 1H NMR spectroscopy, an approach which would make NMR an exceptional tool for non-invasive investigations of integrative physiology and biochemistry in skeletal muscle in vivo.
许多器官的组织灌注和氧合可通过各种核磁共振技术进行评估。本综述重点关注用于研究人类和动物模型骨骼肌灌注和氧合的现有核磁共振工具的特异性、局限性及适应性。同时还介绍了如何将这些工具同时使用。肌红蛋白（Mb）的1H核磁共振波谱可监测肌细胞内的氧合情况。它测量脱氧肌红蛋白的水平，由此可计算出肌红蛋白浓度、肌红蛋白去饱和/再饱和速率、肌肉氧合变化及细胞内局部氧分压（pO2）。骨骼肌中存在正性和负性血氧水平依赖（BOLD）对比。BOLD对比主要反映毛细血管-静脉氧合的变化，但也直接或间接依赖于肌肉血容量、灌注、血管网络结构及相对于主磁场的角度。动脉自旋标记（ASL）技术具有高空间和时间分辨率，是无创定量和绘制骨骼肌灌注图的首选方法。ASL的局限性在于对比度噪声比差和对运动敏感；然而，通过引入特定的适应性改进，已证明在静息和运动期间都可以测量骨骼肌灌注。将这些核磁共振测量与其他测量结合到一个单一动态方案中的可能性非常有趣。“多参数功能（mpf）核磁共振”概念可以扩展到同时用31P核磁共振或乳酸双量子滤波1H核磁共振波谱评估肌肉能量代谢，这种方法将使核磁共振成为体内无创研究骨骼肌综合生理学和生物化学的卓越工具。
