三角扫描磁场下磁化率虚部磁性颗粒成像优化  

Optimization of magnetic particle imaging based on imaginary part of magnetic susceptibility in triangular focus field

作　　者：姜韬[1] 崔鑫超 顾宁 刘文中[1,3] JIANG Tao;CUI Xinchao;GU Ning;LIU Wenzhong(School of Artificial Intelligence and Automation,Huazhong University of Science and Technology,Wuhan 430074,China;School of Biomedical Engineering and Information,Nanjing Medical University,Nanjing 211166,China;China-Poland Belt and Road Joint Laboratory on Measurement and Control Technology,Wuhan 430074,China)

机构地区：[1]华中科技大学人工智能与自动化学院,湖北武汉430074 [2]南京医科大学生物医学工程与信息学院,江苏南京211166 [3]中国-波兰测控技术“一带一路”联合实验室,湖北武汉430074

出　　处：《华中科技大学学报（自然科学版）》2024年第11期101-109,共9页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：科技部重点研发计划基金资助项目(2022YFE0107500,2022YFE0204700);国家自然科学基金资助项目(61973132)。

摘　　要：针对虚部磁性颗粒成像中由三角波扫描磁场传递到浓度测量环节的系统性串扰问题,研究了一种余弦激励磁场下的分段平均方法,以抑制磁化率虚部磁性颗粒成像中的虚假相位波动.使用三角波扫描磁场替代阶梯三角波,分析了三角波扫描磁场对虚部磁性颗粒成像的影响.基于正向和反向扫描的磁化信号,构建了分段平均模型,以抵消扫描磁场引入的虚假相位波动.结果表明:对三角波扫描磁场的下降沿和上升沿内的磁化信号进行分段平均有助于消除由三角波扫描磁场带来的扰动,抑制虚假相位波动对虚部成像造成的误差,提高虚部磁性颗粒成像的精度.通过优化扫描磁场参数,基于虚部信息的一维磁性颗粒成像速率得以从2 Hz提升至80 Hz.关于三角波扫描磁场的研究为提高虚部磁性颗粒成像的时空分辨率提供了新思路.Aiming at systemic crosstalk transferred from the triangular focus field to the concentration measurement,a segmented averaging method under a cosine excitation field was investigated to suppress false phase fluctuations in magnetic particle imaging(MPI)based on the imaginary part of complex magnetic susceptibility.A triangular focus field was used instead of a stepped triangular wave,and the impact of the triangular field on imaginary part-based MPI was analyzed.Based on the magnetization signals from forward and reverse scans,a segmented averaging model was constructed to counteract false phase fluctuations introduced by the focus field.Results show that segmentally averaging the magnetization signals during the descending and ascending edges of the triangular focus field helps to eliminate disturbances caused by the triangular field,suppressing the errors introduced by false phase fluctuations and improving the accuracy of imaginary part-based MPI.By optimizing focus field parameters,the rate of one-dimensional MPI based on imaginary information can be enhanced from 2 Hz to 80 Hz.The research on the triangular focus field provides new insights into improving the temporal-spatial resolution of imaginary part-based MPI.

关 键 词：磁性颗粒成像 复数磁化率 点扩散函数 半峰宽度 超顺磁性氧化铁纳米颗粒 三角波扫描磁场 

分 类 号：TP216.1[自动化与计算机技术—检测技术与自动化装置]