Toward Real-Time GPU Implementation of Diverging Beam With Synthetic Aperture Technique With Non-linear Beamforming for a Curvilinear Array

Abstract

Conventional focused ultrasound imaging typically utilizes focused transmit beams in conjunction with a delay-and-sum (DAS) beamformer for reception, which yields optimal image quality only within the focal zone. To overcome this limitation, synthetic transmit aperture (STA) techniques and advanced non-linear beamforming methods are being explored to enhance the quality of ultrasound images. However, implementing these two approaches demands substantial computational resources. Although ultrasound systems utilizing GPU technology have demonstrated potential for real-time processing, their practical application is still limited. Real-time and affordable systems utilizing STA imaging and advanced non-linear beamforming are still not common in practical applications. Furthermore, the use of curvilinear array transducers is yet largely unexplored in the context of STA imaging. In this study, we present a GPU-based real-time affordable system for curvilinear array transducers that employs diverging beam with synthetic transmit aperture technique (DBSAT) imaging with non-linear beamforming. Experimental RF data were acquired using a tissue-mimicking phantom (CIRS Model 040GSE) with a DBSAT and conventional focused beamforming (CFB) sequence implemented on the programmable Verasonics Vantage 64 system equipped with a C5-2 curvilinear array probe. Beamforming was performed using an NVIDIA GeForce RTX 3060 GPU, implementing both DAS and filtered delay multiply and sum (FDMAS) algorithms. The results suggest that DBSAT-FDMAS using a curvilinear transducer yields improved image quality when the virtual source is positioned closer to the transducer, compared to an infinite virtual source distance. Further, reducing the number of receive elements has a minimal effect on image quality. The estimated axial and lateral resolutions for CFB-FDMAS range from 0.56 to 0.86 mm and 0.39 to 0.96 mm, respectively, whereas for DBSAT32-FDMAS, they range from 0.62 to 0.93 mm and 0.30 to 0.79 mm, respectively. The estimated CNR and gCNR values for CFB-FDMAS are 1.34 and 0.78, respectively, while those for DBSAT32-FDMAS are 1.84 and 0.81, respectively. In summary, DBSAT-FDMAS using 32 active receive elements offers enhanced image quality compared to CFB-FDMAS, while maintaining similar execution times. © The Author(s) 2025