Yanagisawa Osamu, Shimao Daisuke, Maruyama Katsuya, Nielsen Matthew
Faculty of Sport Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa, Saitama, 359-1192, Japan,
Eur J Appl Physiol. 2009 Mar;105(5):723-9. doi: 10.1007/s00421-008-0954-9. Epub 2008 Dec 16.
In this study, we assessed the physiological changes after exercising or cooling skeletal muscles on the basis of the apparent diffusion coefficient (ADC) values in magnetic resonance (MR) diffusion-weighted images (DWIs). DWIs of the ankle dorsiflexors were acquired with a 1.5-T MR device before and after exercising (22 subjects) or cooling (19 subjects). The exercise comprised a 5-min walk with the ankles dorsiflexed and a 30-time ankle dorsiflexion. Cooling (0 degrees C) of the ankle dorsiflexors was performed for 30 min. ADC values were calculated as ADC1-reflecting diffusion and perfusion and ADC2-approximating the true diffusion coefficient of the ankle dorsiflexors before and after exercising or cooling. ADC1 and ADC2 significantly increased with exercise and decreased with cooling (P < 0.05). Considering both diffusion and perfusion, ADC values allowed us to evaluate the intramuscular changes induced by exercising or cooling in terms of the motion of water molecules and microcirculation.
在本研究中，我们基于磁共振（MR）扩散加权成像（DWI）中的表观扩散系数（ADC）值，评估了锻炼或冷却骨骼肌后的生理变化。在锻炼（22名受试者）或冷却（19名受试者）前后，使用1.5-T MR设备采集踝背屈肌的DWI。锻炼包括踝关节背屈状态下5分钟的行走以及30次踝关节背屈动作。对踝背屈肌进行30分钟的冷却（0摄氏度）。计算锻炼或冷却前后反映扩散和灌注的ADC1以及近似踝背屈肌真实扩散系数的ADC2。锻炼后ADC1和ADC2显著增加，冷却后则降低（P<0.05）。综合考虑扩散和灌注，ADC值使我们能够根据水分子运动和微循环来评估锻炼或冷却引起的肌肉内变化。
