[논문 리뷰] Far-field compressive ultrasound beamforming

Nikunj Khetan, Jerome Mertz|arXiv (Cornell University)|2026. 03. 23.

Ultrasound Imaging and Elastography인용 수 0

한 줄 요약

이 논문은 KK 빔포밍을 제안한다. 원거리, 평면파 기반의 압축 방법으로 CPWC 초음파 이미징에서 데이터를 k-공간으로 재구성하여 RF 데이터 압축을 대략 한 차원 수준으로 가능하게 하며, 영상 품질은 기존 CPWC DAS와 동일 수준이다.

ABSTRACT

We present a compressive beamforming method for coherent plane-wave compounding (CPWC) ultrasound imaging based on a far-field decomposition of the received radiofrequency (RF) data into virtual plane waves. This decomposition recasts the imaging operation entirely in the spatial frequency domain ($k$-space), allowing direct and flexible control over $k$-space sampling distributions based on the principle of coarrays. We present vernier-type sampling strategies designed to optimize the tradeoff between image contrast and resolution with minimum redundancy, including strategies that favor dense low-frequency sampling for high contrast, shifted schemes that extend the frequency support for improved resolution, and confocal or hybrid compounding schemes that approximate the spatial-frequency transfer function of conventional DAS beamforming. Our method, called KK beamforming, is validated with a calibration phantom and in-vivo human tissue data, demonstrating compression factors of an order of magnitude while maintaining image qualities comparable to conventional DAS. We further demonstrate that KK beamforming yields improvements in computational speed owing to its reduced memory footprint and more efficient cache utilization of the compressed data and associated look-up tables.

연구 동기 및 목표

• 이미지 품질을 희생하지 않으면서 CPWC 데이터 요구를 줄여 데이터 효율적인 초음파 이미징을 촉진한다.
• RF 데이터의 원거리, k-공간 기반 분해를 개발하여 코얼라이(coarrays)를 통한 제어 가능한 샘플링을 가능하게 한다.
• 압축 하의 대비와 해상도를 균형 있게 하는 버니어형 샘플링 전략과 공초점 샘플링 전략을 제안한다.
• KK 빔포밍을 도입하고 팬텀 및 생체 데이터에서 최대 한 차원의 압축 요인을 입증한다.

제안 방법

• Recade RF data into the spatial-frequency domain by a temporal shear and sum operation to obtain RF_theta from RF_u (Eq. 3).
• Form KK beamforming with a fully far-field, plane-wave transmit/receive model; compute B_KK using delays based on s_i and s_o (Eq. 5).
• Control k-space sampling via selectable receive angles theta_o and transmit angles theta_i to achieve vernier-type, shifted, or confocal sampling (Eqs. 6, 9).
• Compounded KK images can be formed coherently or incoherently to trade contrast and resolution (Eqs. 7–8).
• Reduce memory and compute load with triangular/layered look-up tables and FFT-based processing; compare performance against conventional CPWC DAS.

실험 결과

연구 질문

• RQ1 Can KK beamforming achieve substantial RF data compression for CPWC without severe degradation in image quality?
• RQ2 How does controlling transmit/receive angular sampling in k-space affect image contrast and resolution?
• RQ3 What are the tradeoffs between coherent, incoherent, and hybrid KK compounding in terms of image quality and data compression?

주요 결과

• KK beamforming achieves data compression factors up to an order of magnitude while preserving image quality comparable to conventional CPWC DAS.
• Different k-space sampling schemes (vernier-type, shifted, confocal) provide tunable tradeoffs between image contrast and resolution.
• Hybrid coherent/incoherent compounding can yield improved contrast under compression, potentially outperforming DAS in some metrics (gCNR).
• In vivo and phantom experiments with a GE9LD linear array show KK can maintain image quality under substantial RF data reduction.
• KK beamforming offers faster processing and reduced memory footprint due to compressed data and efficient LUT usage.