Magnetically mediated thermoacoustic imaging with single coil based on non-uniform magnetic field excitation

In order to eliminate the limitation caused by the use of a uniform magnetic field mode in magnetically mediated thermoacoustic imaging (MM-TAI), non-uniform magnetic field excitation with a single coil for MM-TAI is proposed in this paper. The theoretical model of the electromagnetic field based on time–space separation and acoustic field problems for MM-TAI is solved. For the inverse problem, the heat absorption distribution is reconstructed by the time reversal technique. The reconstructed results are in good accord with the original structure model, and the image can be clearly identified and agree well with the electric conductivity model. The experimental system is optimized to test the method, then the phantoms with conductivities of 8 S/m and 7 S/m are used for thermoacoustic signal detection and imaging. The signal detecting ability of the low conductivity target has improved significantly. These results provide the basis of MM-TAI for further application in biomedical imaging.