Ultrasonic method and system for estimating the nonlinear shear wave elasticity of a medium

The invention relates to an ultrasonic method for estimating a nonlinear shear wave elasticity of a medium, the method comprising the following steps: a first 5 collection step in which a first set comprising one shear wave elasticity data point of the medium is collected at a first level of deformation applied to the medium, a second collection step in which a second set comprising one shear wave elasticity data point of the medium is collected at a second level of deformation applied to the medium different to the first level, a deformation 10 estimation step in which the difference of deformation between the first and the second level of deformation is estimated, a calculation step in which a gradient between at least two data points respectively belonging to the first and the second set is calculated as a function of the difference of deformation between the first and the second level of deformation, and an elasticity estimation step 15 in which the nonlinear shear wave elasticity of the medium is estimated as a function of the gradient. Fig. 1