Laboratoire de Physique de la Matière Condensée, CNRS-Ecole Polytechnique, F-91128 Palaiseau, France.
J Magn Reson. 2011 Feb;208(2):243-55. doi: 10.1016/j.jmr.2010.11.009. Epub 2010 Nov 17.
A new method for computing the signal attenuation due to restricted diffusion in a linear magnetic field gradient is proposed. A fast random walk (FRW) algorithm for simulating random trajectories of diffusing spin-bearing particles is combined with gradient encoding. As random moves of a FRW are continuously adapted to local geometrical length scales, the method is efficient for simulating pulsed-gradient spin-echo experiments in hierarchical or multiscale porous media such as concrete, sandstones, sedimentary rocks and, potentially, brain or lungs.
提出了一种新的方法来计算线性磁场梯度中受限扩散引起的信号衰减。该方法将快速随机游走（FRW）算法与梯度编码相结合，用于模拟扩散自旋载体粒子的随机轨迹。由于 FRW 的随机移动不断适应局部几何长度尺度，因此该方法非常适合模拟混凝土、砂岩、沉积岩等层次或多尺度多孔介质中的脉冲梯度自旋回波实验，并且可能适用于大脑或肺部。
