Speed of Sound Estimation at Multiple Angles from Common Midpoint Gathers of Non-Beamformed Data

Sound speed estimation is a promising quantitative parameter in ultrasound for both for it's potential as a biomarker, where sound speed is known to be correlated with biological changes, and for aberration correction, where knowledge of the sound speed allows for correction of distortions in the image. Previous methods for sound speed estimation rely on the use of an a-priori sound speed for beamforming, from which sound-speed estimates are then calculated. However, this assumption introduces a bias in the estimation technique, because errors in the a-priori sound speed lead to distortions in the image. Here we present a method for sound speed estimation that avoids this bias by estimating the sound speed without beamforming.