Numerical Studies for Magneto-Acousto-Electrical Tomography with Magnetic Field Measurement Using Linear Frequency Modulated Excitation

Magneto-acousto-electrical tomography (MAET) is an imaging method based on measurements of the electric current induced by the Lorentz force. This current is generated when an acoustic wave propagates through a conducting body in the presence of a static magnetic field. The resulting current generates an electric potential and magnetic field distribution on the body surface. The surface potential measured by electrodes placed on the body or the magnetic fields measured by receiver coils placed near the body are used to reconstruct the electrical properties of tissues. In this study, the feasibility of the pulse compression method to the MAET with magnetic field measurement is investigated through numerical studies. A numerical breast model with a tumor inhomogeneity is formed. In order to apply the pulse compression method, a linear frequency modulated (LFM) excitation signal is applied to the ultrasound transducer. Additive white Gaussian noise is added to the MAET signal detected by the coils. In this case, the signal-to-noise ratio is increased by using a matched filter of pulse compression method and it is shown that MAET signals of a 2 mm x 2 mm tumor can be obtained. Moreover, the axial resolution that can be obtained with a conventional single pulse excitation can be achieved with the bandwidth selected in the applied LFM excitation signal.