Computational and Mathematical Methods in Medicine
Volume 2013 (2013), Article ID 161357, 13 pages
http://dx.doi.org/10.1155/2013/161357
Research Article

Numerical Study of Magnetoacoustic Signal Generation with Magnetic Induction Based on Inhomogeneous Conductivity Anisotropy

1College of Computer Science, Hangzhou Dianzi University, Hangzhou 310018, China
2College of Life Information Science and Instrument Engineering, Hangzhou Dianzi University, Hangzhou 310018, China
3College of Electrical Engineering, Zhejiang University, Hangzhou 310027, China

Received 20 December 2012; Revised 18 February 2013; Accepted 18 February 2013

Academic Editor: Kumar Durai

Copyright © 2013 Xun Li et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Magnetoacoustic tomography with magnetic induction (MAT-MI) is a noninvasive imaging modality for generating electrical conductivity images of biological tissues with high spatial resolution. In this paper, we create a numerical model, including a permanent magnet, a coil, and a two-layer coaxial cylinder with anisotropic electrical conductivities, for the MAT-MI forward problem. We analyze the MAT-MI sources in two cases, on a thin conductive boundary layer and in a homogeneous medium, and then develop a feasible numerical approach to solve the MAT-MI sound source densities in the anisotropic conductive model based on finite element analysis of electromagnetic field. Using the numerical finite element method, we then investigate the magnetoacoustic effect of anisotropic conductivity under the inhomogeneous static magnetic field and inhomogeneous magnetic field, quantitatively compute the boundary source densities in the conductive model, and calculate the sound pressure. The anisotropic conductivity contributes to the distribution of the eddy current density, Lorentz force density, and acoustic signal. The proposed models and approaches provide a more realistic simulation environment for MAT-MI.