Filtered Delay Multiply and Sum Combined with Space-Time Smoothing Coherence Factor in Ultrasound Imaging

摘要

The Filtered Delay multiply and Sum method was proposed to gain a significantly higher contrast resolution than Delay and Sum beamforming. However, the side or grating lobes caused by the signal coherence still exist. For suppression of the disturbance signals arising from the objectives on the side lobes or grating lobes in the Filtered Delay multiply and Sum beamforming, space-time smoothing coherence factor is adopted. The proposed method was evaluated by both simulation and experiment data. The performance was compared with that of Delay and Sum method, Filtered Delay multiply and Sum method, Filtered Delay multiply and Sum weighted by the space-time smoothing sign coherence factor, respectively. By comparing the Point Spread Functions, it is shown that the proposed method performs better than the other three methods in contrast resolution in both simulated and experimental tests. Additionally, the proposed method can enhance contrast ratio (about 19 dB) and contrast to noise ratio (about 3 dB) for the anechoic cyst than DAS while it can enhance contrast ratio (about 14 dB) and contrast F-DMAS.