Acoustic nonlinearity parameter of tissue on echo mode: review and evaluation of the different approaches for B/A imaging

The nonlinear B/A parameter induces the distortion of ultrasound waves in tissue. Media with different nonlinear parameter differently distort the ultrasound wave. This paper reviews the techniques that allow to compute this parameter in echo mode imaging. For non homogeneous B/A medium, new formulations are proposed. The simulation results show the capacity of all methods to accurately compute the B/A parameter when diffraction effects of the probe are set off, while only the comparative method works nicely when diffraction is taken into account. First experimental results are also presented, confirming the good performance obtainable with such method.