Reduction of nonlinear contrast agent scattering due to nonlinear wave propagation

Wave propagation in tissue and scattering from ultrasound contrast agents are both known to be nonlinear processes at typical frequencies and intensities used in medical ultrasound imaging. The nonlinearity of wave propagation manifests itself mainly as a second harmonic component which will have a phase angle (defined in this paper) relative to the fundamental component. Based on numerical simulations, this paper shows that depending on the relative phase angle between the fundamental and second harmonic component of the pressure pulse incident to the contrast agent, nonlinear contrast agent scattering may be significantly diminished due to this incident pulse distortion.