Keltner J R, Roos M S, Brakeman P R, Budinger T F
Donner Laboratory, Lawrence Berkeley Laboratory, California 94720.
Magn Reson Med. 1990 Oct;16(1):139-49. doi: 10.1002/mrm.1910160113.
The changes in hydrostatic pressure and electrical potentials across vessels in the human vasculature in the presence of a large static magnetic field are estimated to determine the feasibility of in vivo NMR spectroscopy at fields as high as 10 T.A 10-T magnetic field changes the vascular pressure in a model of the human vasculature by less than 0.2%. An exact solution to the magnetohydrodynamic equations describing a conducting fluid flowing transverse to a static magnetic field in a nonconducting, straight, circular tube is used. This solution is compared to an approximate solution that assumes that no magnetic fields are induced in the fluid and that has led previous investigators to predict significant biological effects from static magnetic fields. Experimental results show that the exact solution accurately predicts the magnetohydrodynamic slowing of 15% NaCl flowing transverse to 2.3- and 4.7-T magnetic fields for fluxes below 0.5 liter/min while the approximate solution predicts a much more retarded flow.
为了确定在高达10 T的磁场下进行体内核磁共振波谱分析的可行性，我们估算了在存在强静磁场的情况下人体脉管系统中血管内流体静压和电势的变化。在人体脉管系统模型中，10 T的磁场使血管压力变化小于0.2%。我们采用了磁流体动力学方程的精确解，该方程描述了在非导电的直圆形管中，导电流体横向流过静磁场的情况。将此精确解与一个近似解进行比较，该近似解假定流体中不会感应出磁场，而此前的研究人员据此预测静磁场会产生显著的生物学效应。实验结果表明，对于流速低于0.5升/分钟的情况，精确解能准确预测15%氯化钠溶液横向流过2.3 T和4.7 T磁场时的磁流体动力学减速情况，而近似解预测的流速则要慢得多。
