Numerical Studies for Magneto-Acousto-Electrical Tomography with Magnetic Field Measurement Using Barker Coded Excitation.

Magneto-acousto-electrical tomography (MAET) is an imaging technique that utilizes the measurement of electrical currents induced by Lorentz force. This paper investigates the feasibility of applying the pulse compression method to MAET with magnetic field measurements through numerical studies. A numerical breast model with three tumor inhomogeneities of different lengths and at different depths from the transducer surface is employed. The ultrasound transducer is excited with 7-bit and 13-bit Barker codes for pulse compression. Additive white Gaussian noise is introduced to the MAET signal sensed by the receiver coils. The results demonstrate that pulse compression method leads to improvements of 14.77 dB and 17.41 dB in the signal-to-noise ratio (SNR), compared to the conventional single-cycle excitation, for 7-bit and 13-bit Barker codes, respectively. A tumor as small as 4 mm x 2 mm can be detected at an SNR of 8.96 dB with the usage of 13-bit Barker code excitation, achieving an axial resolution of 2 mm. The selected time duration of the transmitted code in the applied Barker code excitation allows for attaining the same axial resolution as the single-cycle excitation.