中文摘要：

感应式磁声成像（MAT-MI）是一种融合磁感应技术和超声断层扫描技术的新型生物电阻抗成像方法,兼具电阻抗功能成像和超声技术高空间分辨率的优点。目前针对声源重建大都采用时间反转法,该方法存在的问题有：求导数后对数据噪声有放大作用;声压的边缘Gibbs效应导致重建图像的伪影重等。为此,本文对已有的格林函数积分解进行离散,提出一种矩阵投影格式,并在此基础上提出一种迭代求解的算法。为了验证新方法的正确性,我们使用电导率具有空间分布3Dphantom模型进行了数值模拟并获得了不同截面处的声压波形。最后使用本文提出的方法由获得的声压重建得到了高精度的声源分布和电导率分布。

英文摘要：

Magnetoacoustic tomography with magnetic induction（MAT-MI） is a new electrical impendence tomography technique to do non-invasive electrical conductivity imaging of biological tissue at ultrasound imaging resolution.In the present study,the time reversal method is mostly used for reconstructing the acoustic source.However,this method has the following problems： it will strengthen the noise after derivation,and the Gibbs effect in the edge of the acoustic pressure will lead to heavy artifacts for reconstruction.In this work,we investigated a matrix projection formulation according to the proposed integral equation of the Green’s function.In addition,an algorithm based on the system matrix was proposed.In order to demonstrate the validity of the new method,numerical simulation was performed by the 3D phantom model and we got the pressure waveforms at different cross-sections.Finally,using the proposed method and the obtained pressure,we reconstructed the acoustic source and the conductivity distribution with high-resolution.