Mechanical Model of Neural Tissue Displacement During Lorentz Effect Imaging
Mechanical Model of Neural Tissue Displacement During Lorentz Effect Imaging
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DOI：
10.1002/mrm.21772
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发表时间：
2009-01-01
影响因子：
3.3
通讯作者：
Basser, Peter J.
中科院分区：
文献类型：
--
作者：
Roth, Bradley J.;Basser, Peter J.
Allen Song及其同事最近提出了一种名为“洛伦兹效应成像”的神经生物电流核磁共振检测方法。当暴露在磁场中时，神经电流受到移动神经的洛伦兹力。如果位移足够大，则在MR信号中预测伪影。在这项工作中，分析了半径为a的神经在半径为b的周围组织中的位移和剪切模数u。神经携带电流密度J，位于磁场B中。由此产生的弹性问题的解表明，神经在(b/a)中移动距离Bj/4µa(2)。使用4T视野中人类正中神经的实际参数，计算出的位移为0.013微米或更小。移位的分布遍及整个组织，并不局限于神经附近。这种移位的数量级太小，无法用传统的MRI方法检测到。《疯狂的麦根》61：59--，2009，(C)2008威利-利斯股份有限公司。
Allen Song and coworkers recently proposed a method for MRI detection of biocurrents in nerves called "Lorentz effect imaging." When exposed to a magnetic field, neural currents are subjected to a Lorentz force that moves the nerve. If the displacement is large enough, an artifact is predicted in the MR signal. In this work, the displacement of a nerve of radius a in a surrounding tissue of radius b and shear modulus mu is analyzed. The nerve carries a current density J and lies in a magnetic field B. The solution to the resulting elasticity problem indicates that the nerve moves a distance BJ/4 mu a(2)In(b/a). Using realistic parameters for a human median nerve in a 4T field, this calculated displacement is 0.013 mu m or less. The distribution of displacement is widespread throughout the tissue, and is not localized near the nerve. This displacement is orders of magnitude too small to be detected by conventional MRI methods. Magn Reson Mad 61:59-64, 2009, (C) 2008 Wiley-Liss, Inc.