An approach to multibeam covariance matrices for adaptive beamforming in ultrasonography

摘要: Medical ultrasound imaging systems are often based on transmitting, and recording the backscatter from, a series of focused broadband beams with overlapping coverage areas. When applying adaptive beamforming, separate array covariance matrix for each image sample is usually formed. The data used to estimate any one these matrices limited recorded from single transmitted beam, or that some adjacent through additional focusing at reception. We propose form, radial distance, covering all beams. estimated by combining samples after sequenced time delay phase shift. identical performed in conventional delay-and-sum beamforming. performance proposed approach conjunction Capon beamformer studied both simulated scenes consisting point targets phantom specially adapted commercial scanner. results show more capable resolving gives better defined cyst-like structures speckle images compared approach. Furthermore, it shows an increased robustness noise ability resolve point-like traditional per-beam beamformer.