Based on the principles of the Hall effect for ultrasound excitation and wave propagation in a static magnetic field,the theory of ultrasound induced Hall voltage generation is derived in explicit formulae with consideration of the acoustic radiation for a planar transducer.It is proved by numerical simulations that the induced Hall voltage is mainly generated at the conductivity boundary and can be used to map the spatial variation of the conductivity value along the acoustic transmission path.Both the simulated Hall voltage and the reconstructed image show good agreement with the experimental results of Wen[Ultrasonic Imaging 20(1998)206,21(1999)186].The promising simulation results suggest the potential of implementing medical electrical impedance imaging by means of ultrasound induced Hall effect imaging.
Magnetoacoustic tomography with magnetic induction has shown potential applications in imaging the electrical impedance for biological tissues. We present a novel methodology for the inverse problem solution of the 2-D Lorentz force distribution reconstruction based on the acoustic straight line propagation theory. The magnetic induction and acoustic generation as well as acoustic detection are theoretically provided as explicit formulae and also validated by the numerical simulations for a multilayered cylindrical phantom model. The reconstructed 2-D Lorentz force distribution reveals not only the conductivity configuration in terms of shape and size but also the amplitude value of the Lorentz force in the examined layer. This study provides a basis for further study of conductivity distribution reconstruction of MAT-MI in medical imaging.
