Imaging biological tissues with electrical conductivity contrast below 1 S m-1 by means of magnetoacoustic tomography with magnetic induction

Magnetoacoustic tomography with magnetic induction (MAT-MI) is a recently introduced imaging modality for noninvasive electrical impedance imaging, with ultrasound imaging resolution and a contrast reflecting the, electrical conductivity properties of tissues. However, previous MAT-MI systems can only image samples that are much more conductive than real human or animal tissues. To image real biological tissue samples, a large-current-carrying coil that can give stronger magnetic stimulations and stronger MAT-MI acoustic signals is employed in this study. The conductivity values of all the tissue samples employed in this study are also directly measured using a well calibrated four-electrode system. The experimental results demonstrated the feasibility to image biological tissues with electrical conductivity contrast below 1.0 S/m using the MAT-MI technique with safe level of electromagnetic energy applied to tissue samples. (c) 2010 American Institute of Physics. [doi:10.1063/1.3486685]