Conductivity Reconstruction for Magnetically Mediated Thermoacoustic Imaging

Magnetically Mediated Thermoacoustic Imaging (MMTAI) is a noninvasive imaging approach for electrical impedance tomography, which takes the advantages of the high spatial resolution of ultrasound and high contrast of the electrical impedance tomography. In previously reported research on MMTAI, only were metal samples used in experiments and were the acoustic sources reconstructed, no conductivity distribution being reconstructed. This paper reported a conductivity reconstruction algorithm based on the time reversal. Firstly, the analytical formula for the acoustic pressure was established in the forward problem. Secondly, the time reversal algorithm was implemented to reconstruct the conductivity on MMTAI in the inverse problem. At last, both the numerical simulation and the experimental study were conducted to show the performance of the MMTAI with low conductivity phantoms like biological tissues. The acoustic signals and the reconstructed images of the phantoms were also obtained to evaluate the reconstructed conductivity distribution using the proposed method. The reconstructed images were in good agreement with the conductivity information of the phantoms. The simulation and experimental results demonstrated that the MMTAI approach is capable of conductivity reconstruction in a physical setting.