Double Stage Delay Multiply and Sum Beamforming Combined With Full-Lag Spatial Coherence in Ultrasound Imaging

Abstract

Delay multiply and sum (DMAS) is a nonlinear beamforming in ultrasound imaging, which utilizes the spatial autocorrelation of the receive aperture. Double stage delay multiply and sum beamforming (DSDMAS) makes use of the delay and sum (DAS) algebra inside the expansion of DMAS formula. It performs better in noise and clutter suppression and resolution improvement than DMAS. However, this imaging method still needs suppressing sidelobe levels and improving resolution further. To address this issue, this paper proposes double stage delay multiply and sum beamforming combined with full-lag spatial coherence (FLSC-DSDMAS). For each imaging point, double stage delay multiply and sum beamformed signals are weighted by the corresponding full-lag spatial coherence. Simulated results verify the validation of the proposed method. The -6dB mainlobe width of the proposed method is 0.44mm while they are 0.99mm, 0.60mm, 2.68mm and 4.50mm for DAS, DMAS, DSDMAS, SLSC20 and RSLSC20, respectively. The contrast ratio (CR) of the proposed method for anechoic area is higher than that of DAS, DMAS, DSDMAS, SLSC20 and RSLSC20 up to 8.31dB. Meanwhile, the contrast ratio of the proposed method for hyperechoic area is higher than that of DAS, DMAS, DSDMAS, SLSC20 and RSLSC20 up to 18.36dB.