Nonlinear beamforming of aperture domain signals

Image quality continues to be a challenge for medical ultrasound. Recent evidence implicates wavefront distortion from sound speed inhomogeneity and reverberation. To target the reverberation problem, we developed an algorithm called Aperture Domain Model Image REconstruction (ADMIRE). ADMIRE explicitly models, identifies and suppresses acoustic clutter resulting from multipath or off-axis scattering. Also because multipath scattering can be hard to study, we introduce a new method for obtaining pulse-echo measures of reverberation from ex vivo tissue samples. We demonstrate that ADMIRE improves contrast and CNR by 7.1±2.5 dB and 0.86±0.92 dB, respectively. We also apply ADMIRE to multipath scattering from a porcine abdominal wall layer and show that we can reduce the relative clutter level by 13 dB compared to standard beamforming.