A fast calculation method for magnetic field inhomogeneity due to an arbitrary distribution of bulk susceptibility
A fast calculation method for magnetic field inhomogeneity due to an arbitrary distribution of bulk susceptibility
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DOI：
10.1002/cmr.b.10083
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发表时间：
2003-10-01
影响因子：
0.9
通讯作者：
Moonen, CTW
中科院分区：
文献类型：
--
作者：
Salomir, R;De Senneville, BD;Moonen, CTW
由于磁化率的（动态）变化而引起的磁场分布的快速计算方法可以允许实时介入应用。这里示出了使用麦克斯韦的静磁方程的一阶扰动方法可以获得磁保持扰动和MR磁体内部的磁化率分布之间的直接关系，结合傅里叶变换技术求解偏导数方程，数学形式不涉及任何限制的形状或均匀性的磁化率举行。如果磁化率范围不超过10（4）（或100 ppm），则一阶近似值就足够了。该形式主义允许使用3D矩阵进行快速数值计算。对于128 X 128 X 128矩阵大小，PC上的几秒钟计算时间就足够了。预测的相位图符合分析和实验数据在1%的精度。(C)2003 Wiley Periodicals，Inc.
A fast calculation method for the magnetic field distribution due to (dynamic) changes in susceptibility may allow real-time interventional applications, Here it is shown that a direct relationship can be obtained between the magnetic held perturbation and the susceptibility distribution inside the MR magnet using a first order perturbation approach to Maxwell's magneto-static equations, combined with the Fourier transformation technique to solve partial derivative equations, The mathematical formalism does not involve any limitation with respect to shape or homogeneity of the susceptibility held. A first order approximation is sufficient if the susceptibility range does not exceed 10(4) (or 100 ppm. The formalism allows fast numerical calculations using 3D matrices. A few seconds computation time on a PC is sufficient for a 128 X 128 X 128 matrix size. Predicted phase maps fitted both analytical and experimental data within 1% precision. (C) 2003 Wiley Periodicals, Inc.