Beamforming using spatio-temporal filtering

Wiener spatial filtering of unfocused echo signals in the near field of low f-number apertures is a promising beamforming strategy for detecting low-contrast lesions. The advantages of the spatial filter over dynamic receive focusing (DRF) include greater echo signal-to-noise ratio (eSNR) and improved proved lateral resolution. Disadvantages include sidelobe growth and a loss of eSNR gain in the far field. Temporally coded pulses enhance eSNR at all depths, but generate the lowest range sidelobes in the far field. Temporal codes are distorted in the near field of low f-number apertures, unless filtering is applied to individual receive channels. In this paper we combine the best of both techniques with the goal of enhancing low contract breast lesion visibility. Experiments and simulations illustrate the advantages and limitations of the spatio-temporal filtering method.