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。重建涡流场有旋分量的模值可以避免洛伦兹力的散度在边界处的奇异性、能够获得分辨率更好的电导率图像。本文对涡流场有旋分量的方向进行了分析，对格林函数解的积分项进行化简，提出一种基于涡流场有旋分量模值的电导率重建方法。为了验证新方法的正确性，我们使用电导率具有空间分布的两种模型进行了数值模拟，并使用新方法快速地重建得到高精度的电导率分布。

英文摘要：

Magnetoacoustic tomography with magnetic induction （MAT-MI） is a new electrical impendence tomography technique for non-invasive electrical conductivity imaging of biological tissue at ultrasound imaging resolution. Reconstructing the modulus value of the rotational part of the eddy current field can avoid the divergence of the singularity at the boundary, and thus obtain a better resolution of the conductivity distribution. In this work, we analyzed the direction of the rotational part of the eddy current field, simplified the integral term of the Green＇s function solution and investigated a new method to reconstruct the conductivity based on the modulus value of the rotational part of the eddy current field. In order to demonstrate the validity of the new method ,numerical simulation was performed by two models with conductivity of the spatial distribution, and using the new method we obtained the accurate reconstruction of the conductivity distribution quickly.