电工技术学报2025，Vol.40Issue(6)：1718-1728,11.DOI:10.19595/j.cnki.1000-6753.tces.240394
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
摘要
Abstract
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 condition,with maximum detection errors of 0.51%and 1.51%on the center and edge planes.(3)The maximum detection errors of FFP and FFL scanning movement cases can be reduced from 1.977%and 1.51%of the third harmonic detection to 1.247%and 0.98%of the second harmonic detection. The following conclusions can be drawn.(1)In FFP or FFL scanning movement,the detection performance of the proposed device is closer to the ideal detection than the two traditional open detection devices,which is suitable for the X-space and PR imaging algorithms.(2)When the proposed device is considered for the image reconstruction,the second harmonic detection helps to reduce the detection errors and improve detection results compared to the third harmonic detection.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Key words
Magnetic particle imaging/open detection device/detection signal/magnetic field uniformity/square Helmholtz coil分类
信息技术与安全科学引用本文复制引用
汤云东,丁宇彬,金涛..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[J].电工技术学报,2025,40(6):1718-1728,11.基金项目
国家自然科学基金(62071124,62471144)和巴西国家科学技术发展委员会(309244/2018-8)资助项目. （62071124,62471144）
