P2E-5 A New Numerical Approach to Simulate Shear Waves Generated by a Localized Radiation Force in Heterogeneous Media

Shear wave elastography imaging consists in following the shear wave propagation induced by a localized radiation force in soft tissue. In order to correctly solve the inverse problem to determine the Young's modulus spatial repartition from the shear wave velocity, we need to precisely understand the different physical effects which influence the propagation of this wave (diffraction, attenuation and elasticity). To simulate heterogeneous media, we developed a numerical model based on the pseudo-spectral method. We propose in this work an approach to separate shear and compression contributions, and then to only follow the shear wave generated by a localized radiation force. We performed independent simulations of the compression and shear waves propagation induced by a punctual force in a homogeneous tissue. Moreover, we simulated the compression and shear waves propagation in an heterogeneous tissue comprising an inclusion with a different Young's modulus from the surrounding medium. The shear wavefront deformation, as well as the diffraction and reflection of the shear wave, can be analyzed