基于迭代补偿的纳米粒子磁化信号检测方法研究

磁粒子成像是一种无创成像技术，通过检测磁粒子示踪剂磁化信号，表征其浓度分布图像。在实际检测中，检测线圈的感应信号包含激励磁场信号与磁性纳米粒子磁化信号。将激励信号从感应电压中去除，获取粒子信号是磁性粒子成像信号检测需要解决的关键问题。针对磁性纳米粒子成像信号检测中激励磁场耦合消除方法进行研究，设计平面梯度检测线圈，并提出迭代补偿控制方法，消除激励磁场耦合，实现磁性纳米粒子磁化信号检测。仿真计算与实验测量的结果表明，对于不同检测模型，所提出的检测方法均可以完成粒子信号检测。该方法获得的粒子信号的信噪比是原有信号消去检测方法的2.2倍，与滤波方法相比信噪比提高到1.3倍，激励磁场耦合衰减可达到34 dB。

A detection method of magnetization signal of nanoparticles based on iterative compensation

Magnetic particle imaging (MPI) belongs to the non-invasive imaging technology, which can characterize the concentration distribution of magnetic particle by detecting the magnetization signal of magnetic particle tracer. When it is utilized to detect the magnetization signal of magnetic nanoparticles, how to remove the excitation signal from the induced voltage is a key problem to be solved. The method for removing the excitation magnetic field feed-through in magnetic nanoparticles imaging signal detection is studied. The planar gradient detection coil is designed, and an iterative compensation control method is proposed to eliminate the excitation magnetic field coupling. In this way, the magnetization signal detection of magnetic nanoparticles is realized. Simulation computing and experimental results show that particle signal detection for different detection models can be realized by the proposed detection method. The signal-to-noise ratio of the particle signal obtained by this method is 2. 2 times that of the original detection method and 1. 3 times that of the filtering method. The excitation magnetic field feed-through suppression is up to 34 dB.