磁共振射频发射与接收线圈谐振电路特性仿真分析  

Resonant circuit characteristics of magnetic resonance radiofrequency transmitter and receiver coils:a simulation analysis

作　　者：黄清明 郑刚[2,4] HUANG Qingming;ZHENG Gang(School of Medical Imaging,Shanghai University of Medicine&Health Sciences,Shanghai 201318,China;School of Optical-Electrical and Computer Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China;Shanghai Key Laboratory of Molecular Imaging,Shanghai 201318,China;Institute of Medical Imaging Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海健康医学院医学影像学院,上海201318 [2]上海理工大学光电信息与计算机工程学院,上海200093 [3]上海市分子影像重点实验室,上海201318 [4]上海理工大学医学影像工程研究所,上海200093

出　　处：《中国医学物理学杂志》2020年第10期1272-1280,共9页Chinese Journal of Medical Physics

基　　金：国家重大科学仪器设备开发专项资助项目(2013YQ170463);上海市高校“高峰高原”学科Ⅱ类高原学科建设项目;上海健康医学院教师教学能力专项“培优计划”项目[PY(19)06-G1-01];“教师专业发展工程”上海高校教师培养计划产学研践习项目。

摘　　要：目的:使射频线圈的工作频率接近于磁共振成像(MRI)的共振频率,即射频线圈处于谐振状态,从而提高MRI系统射频功率的转化效率、改善MRI图像质量。方法:在介绍MRI射频线圈谐振电路原理的基础上,对射频线圈串联谐振电路和并联谐振电路进行理论推导。采用电子电路设计软件MULTISIM搭建串联谐振电路和并联谐振电路,从射频脉冲作用瞬间、正弦稳态和射频脉冲撤除后3个阶段,分别对其谐振电路波形、幅频特性、相频特性、线圈两端的瞬时压降和稳态电路参数等进行仿真模拟分析。结果:电子线路仿真的结果能够直观地反映串联谐振电路和并联谐振电路的特性。通过电子线路参数的优化调整能使射频线圈处于最佳谐振状态,从而提高射频功率的转化效率和改善MRI图像质量。结论:谐振电路特性的仿真分析为射频线圈的设计提供了技术依据,提高了工作效率,节约了射频线圈谐振电路的设计制造成本。Objective To improve the conversion efficiency of radio frequency(RF)power and the quality of magnetic resonance imaging(MRI)by making the working frequency of RF coil close to the resonance frequency of MRI,ensuring RF coil in resonance state.Methods On the basis of introducing the principle of resonant circuit of RF coil inMRI,the series resonance circuit and parallel resonance circuit of RF coil were deduced theoretically.The series resonant circuit and parallel resonant circuit were constructed by the electronic circuit design software MULTISIM.The waveform,amplitude-frequency characteristics,phasefrequency characteristics,instantaneous voltage drop and steady-state circuit parameters of the resonant circuits were simulated and analyzed in 3 phases,namely instantaneous action of RF pulse,sinusoidal steady-state and after the removal of RF pulse.Results The electronic circuit simulation results directly reflected the characteristics of series resonant circuit and parallel resonant circuit.The RF coil was in the optimal resonant state by optimizing and adjusting the parameters of electronic circuit,thus improving the conversion efficiency of RF power and improving the quality of MRI image.Conclusion The simulation analysis of the characteristics of resonant circuit provides a technical basis for the design of RF coil,improves the working efficiency and saves the cost of the design and manufacture of the resonant circuit of RF coil.

关 键 词：磁共振成像 射频线圈 串联谐振电路 并联谐振电路 

分 类 号：R318[医药卫生—生物医学工程] R443.8[医药卫生—基础医学]