Accelerator Architecture for Plane-Wave Ultrasound Image Reconstruction in Fourier Domain

Abstract

Ultrafast ultrasound imaging based on coherent plane-wave compounding (CPWC) enables very high data acquisition rates in the order of thousands of frames per second. This capability allows the user to capture and characterize fast-changing dynamics of blood flow or tissue motion, thus facilitating advanced biomedical diagnostics. Fast data acquisition should be supported by high image reconstruction rates, which translates into significant computational demands. To address this issue, several state-of-the-art hardware accelerators for CPWC image reconstruction, or beamforming, have been reported in the literature. They primarily target time-domain methods based on delay-and-sum (DAS) beamforming. For the first time, this article proposes a novel hardware architecture for accelerating Fourier-domain image reconstruction, based on an efficient migration technique from geophysics. Our FPGA implementation of one specific architectural instance achieves the reconstruction throughput of 1,380 frames per second (without compounding), where each complex-valued “analytic” image frame consists of $2048\times 128~64$ -bit data samples. The presented work also aims to motivate further research into hardware support for Fourier-domain migration. This technique is asymptotically faster than conventional DAS beamforming; however, its efficient hardware realization is challenging, partly due to its relatively large memory footprint.