MR Centre of Excellence, Department of Radiology, Medical University of Vienna, Vienna, Austria; Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovak Republic.
NMR Biomed. 2013 Dec;26(12):1714-22. doi: 10.1002/nbm.3008. Epub 2013 Aug 16.
Phosphorus magnetic resonance spectroscopy ((31)P-MRS) enables the non-invasive evaluation of muscle metabolism. Resting Pi-to-ATP flux can be assessed through magnetization transfer (MT) techniques, and maximal oxidative flux (Q(max)) can be calculated by monitoring of phosphocreatine (PCr) recovery after exercise. In this study, the muscle metabolism parameters of 13 overweight-to-obese sedentary individuals were measured with both MT and dynamic PCr recovery measurements, and the interrelation between these measurements was investigated. In the dynamic experiments, knee extensions were performed at a workload of 30% of maximal voluntary capacity, and the consecutive PCr recovery was measured in a quadriceps muscle with a time resolution of 2 s with non-localized (31)P-MRS at 3 T. Resting skeletal muscle metabolism was assessed through MT measurements of the same muscle group at 7 T. Significant linear correlations between the Q(max) and the MT parameters k(ATP) (r = 0.77, P = 0.002) and F(ATP) (r = 0.62, P = 0.023) were found in the study population. This would imply that the MT technique can possibly be used as an alternative method to assess muscle metabolism when necessary (e.g. in individuals after stroke or in uncooperative patients).
磷磁共振波谱((31)P-MRS) 可实现肌肉代谢的非侵入性评估。通过磁化转移 (MT) 技术可以评估静止状态下的 Pi 到 ATP 通量，并且可以通过监测运动后磷酸肌酸 (PCr) 的恢复来计算最大氧化通量 (Q(max))。在这项研究中，使用 MT 和动态 PCr 恢复测量来测量 13 名超重肥胖久坐个体的肌肉代谢参数，并研究了这些测量之间的相互关系。在动态实验中，以最大自愿能力的 30%的工作量进行膝关节伸展运动，并使用非局部化（31）在 3T 下以 2s 的时间分辨率对股四头肌进行 P-MRS 连续测量 PCr 恢复。通过 7T 对同一肌肉群的 MT 测量评估静息骨骼肌代谢。在研究人群中发现 Q(max) 与 MT 参数 k(ATP)(r = 0.77，P = 0.002) 和 F(ATP)(r = 0.62，P = 0.023) 之间存在显著的线性相关性。这意味着在必要时（例如在中风后或不合作的患者中），MT 技术可能可以作为评估肌肉代谢的替代方法。
