Morvan D, Leroy-Willig A, Malgouyres A, Cuenod C A, Jehenson P, Syrota A
Service Hospitalier Frédéric Joliot, C.E.A., Orsay, France.
Magn Reson Med. 1993 Mar;29(3):371-7. doi: 10.1002/mrm.1910290313.
The thermal dependence of the translational diffusion coefficient and of the regional blood volume was investigated in vivo by using a special MR pulsed gradient technique with reduced sensitivity to bulk tissue motion. Measurements were done at 0.5 T, using a small gradient insert. The diffusion coefficient of muscle water was calibrated against thermocouple-measured temperature in vitro, both with the muscle fibers parallel and perpendicular to the diffusion gradient. The maximum muscle temperature variation obtained by percutaneous conduction was -8.8 +/- 1.6 degrees C under cooling and +3.7 +/- 1.6 degrees C under heating, from basal state. Simultaneously the fractional regional blood volume decreased by a factor of 3.5 under cooling and increased by a factor of 2.7 under heating. Due to the interdependence of microcirculation and tissue temperature, this technique may be used to follow heat production or deposition in living tissue (muscle exercise, electromagnetic irradiation, etc.).
采用一种对整体组织运动敏感度降低的特殊磁共振脉冲梯度技术，在体内研究了平移扩散系数和局部血容量的热依赖性。使用小型梯度插入件，在0.5T场强下进行测量。在体外，针对热电偶测量的温度校准了肌肉水的扩散系数，测量时肌肉纤维分别平行和垂直于扩散梯度。经皮传导引起的肌肉温度最大变化为，从基础状态开始，冷却时为-8.8±1.6℃，加热时为+3.7±1.6℃。同时，局部血容量分数在冷却时降低了3.5倍，在加热时增加了2.7倍。由于微循环与组织温度相互依存，该技术可用于追踪活体组织（肌肉运动、电磁辐射等）中的产热或热沉积情况。
