Multi-excitation magnetoacoustic tomography with magnetic induction (MAT-MI)

Magnetoacoustic tomography with magnetic induction (MAT-MI) is an approach proposed to do non-invasive electrical conductivity imaging of biological tissue using magnetic induction and ultrasound measurements. In the present study, based on the analysis of the relationship between the conductivity distribution and the generated MAT-MI acoustic source, we propose a new multi-excitation algorithm to achieve better reconstruction of the conductivity distribution. In this algorithm, multiple magnetic excitations using different coil configurations are employed and the ultrasound measurements corresponding to each excitation are collected to derive the conductivity distribution inside the sample. The corresponding modified algorithm is also proposed for MAT-MI imaging when only limited bandwidth acoustic measurements data are available. Computer simulations have been done to demonstrate the performance of the proposed algorithm. It is shown that using this algorithm and unlimited bandwidth data, we can accurately reconstruct the internal conductivity contrast of the object. With limited bandwidth data and using the modified algorithm we can also reconstruct the relative conductivity contrast of the object instead of only the boundaries at the conductivity heterogeneity. Benefits come with this new algorithm include better differentiation of different tissue types with conductivity contrast using MAT-MI approach, specifically for the potential breast cancer screening application in the future.