矩量法及其在磁共振射频线圈中的应用  

Method of Moments and Its Application to Radio -frequency Coils in Magnetic Resonance Imaging System

作　　者：辛学刚[1] 韩继钧[1] 陈武凡[1] 

机构地区：[1]南方医科大学生物医学工程学院

出　　处：《中国医学物理学杂志》2010年第4期2004-2007,2029,共5页Chinese Journal of Medical Physics

基　　金：国家重点基础研究发展规划(973计划No.2010CB732500);国家自然科学基金重点项目(No.30730036)

摘　　要：目的:基于矩量法,实现对具体射频线圈的电磁仿真分析。方法:对不同射频线圈进行建模,基于具体的线圈模型,选取合适的基函数对未知函数进行展开,并代入电磁场下的相应算子方程,从而实现运用矩量法对射频线圈的电磁仿真分析。本文首先通过推导给出矩量法的电磁场计算公式,再将其进行必要的化简,最后通过Matlab工具实现对具体线圈模型的仿真计算。结果:通过对头部线圈,头颈联合线圈以及术中多通道射频接收线圈的仿真,得到电磁场分布结果。结论:与基于比奥-萨法尔定律传统方法计算磁场分布相比,矩量法能够更方便地分析复杂拓扑结构的射频线圈的磁场分布,应用范围更广。同时,该方法比FDTD等方法需要的计算资源少很多,更适合工程设计人员使用。Objective： This study develops a novel method （method of moments, MOM） to simulate the B1 magnetic field dis- tribution of several specific radio-frequency （RF） coils in magnetic resonance imaging system. Methods： The appropriate base functions had been chosen to expand the unknown functions, based on the models of a series of specific RF coils. With these base functions into which the relevant operator equations in electromagnetic field had been carefully substituted, the simulation of the electromagnetic field was accomplished. The process of theoretical derivation was also slightly drawn in this work, and along with the software tool MATLAB, the results were acquired. Results： The results showed that simulations of B1 magnet- ic field distributions of the different coils, including the head coil, the head and neck coil, intra-operative multi-channel receive RF coil, were homogeneous. Conclusions： Compared with the traditional methods of the Biot-Savart＇s law, MOM has the advantage in the analysis of the fairly complicated topological structures of RF coils. And this method was proved more feasible than other methods in term of the computing power.

关 键 词：矩量法 磁共振 射频线圈 

分 类 号：R319[医药卫生—基础医学] O441.4[理学—电磁学]