Post-beamforming second-order Volterra filter for nonlinear pulse-echo imaging

In this paper, we demonstrate that a second-order Volterra filter (SVF) can adequately model pulse-echo imaging data acquired from tissue media. Furthermore, we demonstrate that the coefficients of both the linear impulse response and the second-order kernel can be robustly estimated from imaging data using pseudorandom binary input sequences. The validation of the SVF as an appropriate model for ultrasonic imaging will allow for more intelligent use of post-beamforming signal processing for enhancing image contrast and producing quantitative imaging.