基于脉冲压缩的磁热声成像新方法研究

项目名称： 基于脉冲压缩的磁热声成像新方法研究

项目编号： No.51477161

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 电工技术

项目作者： 刘国强

作者单位： 中国科学院电工研究所

项目金额： 90万元

中文摘要： 磁热声成像是国际上2013年最新提出的多物理场成像方法，融合了电阻抗成像（EIT）的高对比度和超声成像的高空间分辨率的优点，有望解决传统EIT空间分辨率不高的问题。该方法与磁声成像相比省去了静磁场，降低成像系统的复杂度，与微波热声成像相比大大提高了穿透深度。但目前的研究还停留在简单物理模型的初步研究阶段，与临床应用的差距很大。本项目提出一种基于脉冲压缩的医学磁热声成像新方法（MTAT-PCT），采用MHz磁谐振式、线性调制和脉冲压缩相结合的激励检测方式，实现微弱磁热声信号的高信噪比检测。突破生物组织的电场强度与其电导率无关的不合理假定，首次导出包含热函数的非线性泊松方程和双旋度方程，提出了两种从热函数中重建电导率的新方法--基于标量电位的电导率重建方法和基于矢量电位的电导率重建方法，使该技术向实际应用推进一步，形成具有中国自主知识产权的新型高分辨率电阻抗成像方法。

中文关键词： 磁热声；电磁场；脉冲压缩；逆问题；成像

英文摘要： Magnetically mediated thermoacoustic imaging (MM-TAI)is a innovative international multi-physics field imaging method proposed in 2013. This imaging method combines the advantages of high contrast for electrical impedance tomography (EIT) and high spatial resolution of ultrasound imaging, which is hopeful to solve the problem of low spatial resolution of EIT.Compared with magneto-acoustic tomography, MM-TAI system eliminates the static magnetic field, and reduces the complexity of the imaging system. At the meantime, compared with microwave thermo-acoustic imaging, MM-TAI improves the penetration depth of biological tissue greatly. However,the research is still in the stage of simple physical model at present, and there is very great disparity in clinical application.This project proposes an innovative magnet-thermo-acoustic imaging technology, called Magnet-thermo-acoustic tomography based on pulse compress technology (MTAT-PCT). It will be devote to study on the excitation detecting theory which fuses MHz magnetic resonance, linear modulation and pulse compression, and helpful to improve the tomography's signal-to-noise ratio. To break through the unreasonable assumption that electric field strength and electrical conductivity of biological tissue is independent, we first deduce the nonlinear Poisson's equation and double curl equation including the heat function, and propose two rebuilding conductivity algorithms based on the scalar and vector electric potential. As a result,it could be expected to further promote the practical application of this technology, and form a new high resolution EIT method holding independent intellectual property rights.

英文关键词： Magnetically mediated thermo-acoustic;Electromagneitc Field;Pulse Compress;Inverse Problem;Tomography