考虑磁场均匀性优化的开放式磁粒子成像检测装置改进方法  

Research on the Improved Method of Open Detection Device for Magnetic Particle Imaging Considering Magnetic Field Uniformity Optimization

作　　者：汤云东[1] 丁宇彬 金涛[2] Tang Yundong;Ding Yubin;Jin Tao(College of Physics and Information Engineering Fuzhou University,Fuzhou 350108 China;College of Electrical Engineering and Automation Fuzhou University,Fuzhou 350108 China)

机构地区：[1]福州大学物理与信息工程学院,福州350108 [2]福州大学电气工程与自动化学院,福州350108

出　　处：《电工技术学报》2025年第6期1718-1728,共11页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金(62071124,62471144);巴西国家科学技术发展委员会(309244/2018-8)资助项目。

摘　　要：磁粒子成像(MPI)利用检测装置感应可视场内不同位置处磁纳米粒子(MNPs)的非线性磁化响应,并基于所获得的检测信号重建MNPs浓度分布。该文基于激励与接收线圈磁场强度对检测信号的影响,论证了X-space和投影重建成像算法中MPI检测装置磁场均匀性的重要性,继而提出一种由具有较高磁场均匀性的正方形亥姆霍兹线圈所构成的改进开放式检测装置。此外,在零磁场点和零磁场线扫描移动两种情况下,基于不同装置下均匀分布MNPs所获得的检测信号,评估了两种传统开放式检测装置和所提改进装置的检测效果。研究结果表明,所提改进开放式装置的检测结果相比两种传统开放式装置显著接近理想情况,进而也证实了检测装置磁场均匀性的重要性。此外,该文还发现在改进装置基础上采用二次谐波检测方法相较于三次谐波检测,可获得更佳的检测效果。The magnetic field strength of magnetic particle imaging(MPI)detection devices(excite and receive coils)has a direct impact on the detection signal of magnetic nano particle(MNPs)magnetization response.The non-uniformity of the magnetic field makes reconstructing MNP concentration challenging by detection signals in the reconstruction algorithms such as x-space and projection reconstruction(PR).Although the system matrix imaging algorithm or additional correction algorithm can correct the error caused by the non-uniform magnetic field of detection devices,it is complex and costly.Therefore,it is necessary to design a detection device with a highly uniform magnetic field.This study investigated the importance of magnetic field uniformity of MPI detection devices in x-space and PR imaging algorithms after revealing the relationship between the detection signal,the peak intensity of the excitation magnetic field,and the sensitivity of the receiving magnetic field.A modified open detection device with square Helmholtz coils was proposed.The square Helmholtz coil provides a uniform magnetic field while maintaining the detection device’s openness.The detection performance of the proposed and two traditional open detection devices were evaluated in two scenarios:field free point(FFP)and field free line(FFL)scanning movement.It is noted that the ideal detection signals should be consistent within the field of view(FOV)due to the uniform distribution of MNPs.In addition,the results of second-harmonic and third-harmonic detection were compared.Simulation results show that:(1)In the case of FFP scanning movement,the maximum detection errors of the proposed improved open detection device are 0.865%and 1.977%on the center and edge planes,respectively,which are closer to the ideal detection effect than the two traditional ones.(2)The FFL scanning movement shows similar results to the FFP scanning movement,and the detection accuracy of the proposed device is more excellent than the two traditional devices under the same condi

关 键 词：磁粒子成像 开放式检测装置 检测信号 磁场均匀性 正方形亥姆霍兹线圈 

分 类 号：TM154.1[电气工程—电工理论与新技术]