A real-time synthetic aperture beamformer for medical ultrasound imaging

Synthetic aperture (SA) imaging techniques have drawn many attentions since they are capable of providing improved spatial resolution over conventional receive dynamic focusing (CRDF) methods. However, the processing of SA imaging is computationally demanding for real-time processing. Furthermore, massive memories for storing the pre-beamformed radio frequency (RF) data are required, leading to substantial increase in hardware complexity. In this paper, we propose the efficient real-time SA beamformer architecture that could be integrated in modern ultrasound imaging systems. The feasibility of the proposed architecture was demonstrated by implementing a 64-channel SA beamformer on two high-performance field programmable gate arrays (FPGAs, Virtex-5 SX95T, Xilinx, USA). The developed SA beamformer can support up to 12 synthesis beams by utilizing 61% of slice registers, 43% of look up tables (LUTs), 89% of random access memories (RAMs) and 51% of digital signal processing (DSP) blocks in each FPGA.