Reducing Dark Region Artifacts in Short-Lag Spatial Coherence (SLSC) Beamforming by Coherence Filtering of the Aperture-Domain Data

The short-lag spatial coherence (SLSC) beamformer measures the accumulated similarity of echoes, received by individual transducer elements as a function of spatial separation. It proved beneficial in suppressing incoherent clutter to improve detectability of hypoechoic and anechoic targets. However, with focused beams spatial coherence of backscattered echoes drops significantly away from the focal depth, where dark region artifacts occur due to high-level off-axis interference, reducing the effective depth-of-field when using SLSC. This study aimed to suppress this artificial dropout and keep the image uniformity through depths by filtering the aperture-domain data.