Reconstruction of acoustic inhomogeneous property in Magnetoacoustic Tomography with Magnetic Induction

Abstract

Magnetoacoustic Tomography with Magnetic Induction (MAT-MI) is a hybrid imaging modality proposed to reconstruct the electrical impedance property in biological tissue with high spatial resolution. The tissue in most parts of human body has inhomogeneous acoustic properties, which will significantly affect the propagations of ultrasound waves. And then it leads to potential distortion and blurring of the acoustic source and conductivity images in the reconstruction. The purpose of this paper is to reconstruct both the acoustic source and conductivity distribution in an acoustically heterogeneous medium. And a new algorithm is presented based on the generalized finite element method (GFEM) and inhomogeneous time reversal method. We established an acoustic inhomogeneous model, in which different regions of the model the acoustic signals spread with different speeds. The numerical simulation experiments showed feasibility of the new method. Then we applied the proposed algorithm to reconstruct the conductivity of a gel phantom with our MAT-MI system. The experimental results indicate that the acoustic inhomogeneity of tissues in terms of speed variation can be reconstructed in the process of MAT-MI imaging.