A low-rate parallel Fourier domain beamforming method for ultrafast pulse-echo imaging

We present a Fourier domain beamforming method for ultrafast pulse-echo imaging that significantly reduces the number of acquired samples. In its basic form, our proposed method combines the low-rate in-phase and quadrature sampling of the received analog radio frequency (RF) signals and the electronic receive focusing in the temporal Fourier domain. Using both synthetic and in vivo measurement data, the basic form reduced the numbers of acquired samples by 69.9% and 74.97%, respectively, compared to the prevalent fusion of the conventional high-rate sampling of the received analog RF signals and the electronic receive focusing in the time domain. Moreover, the basic form reduced imaging artifacts. In its advanced form, our proposed method additionally imposes a finite rate of innovation model on the analytical focused RF signal. The sparse recovery of the associated model parameters by ℓq-minimization, q ∈ [0; 1], enabled reductions in the numbers of acquired samples by 74.39% and 78.79%, respectively, while the main image features were preserved.