Nonlinearity studies in soft tissues with the supersonic shear imaging system

The ultrafast scanner has been shown to be a powerful tool to detect shear wave propagation within soft tissues in transient elastography experiments. More recently it was also used to generate shear waves thanks to the acoustic radiation pressure. This technique, the supersonic shear imaging, can easily be implemented in an acoustoelasticity experiment. Thus the association of static elastography with dynamic elastography can reveal the nonlinear properties of soft materials. Moreover, using a new theoretical approach of the strain energy in soft solid (Hamilton et al. (2003)), it is shown that the acoustoelasticity experiment can be greatly simplified. Instead of measuring shear wave speed for three different polarizations in order to completely determine the nonlinearity of standard solids, one is sufficient in soft solids to characterize the nonlinear shear elasticity.