2025/06/18 by Leroy, Henri, Bertolo, Adrien, Goudot, Guillaume +3 · 1 citation
#Applied Physics (physics.app-ph) #FOS: Physical sciences #Medical Physics (physics.med-ph)
paper · doi:10.48550/arxiv.2506.15469
Accurate volumetric velocity estimation in ultrasound imaging is crucial for both diagnostic and therapeutic applications. Traditional ultrasound systems, though effective for two-dimensional imaging, face major limitations in 3D imaging due to hardware and computational demands. Row-column addressed (RCA) ultrasound probes offer a promising alternative by reducing hardware complexity, thereby helping bridge the gap between research prototypes and clinical systems. However, this typically comes at the expense of stronger sidelobes compared with fully populated matrix arrays, leading to a decreased signal-to-noise ratio (SNR). In this study, we present a method that exploits the phase information from RCA rows and columns signals to compute a novel velocity estimator based on cross-correlation of orthogonal apertures. This extends the XDoppler scheme, initially developed for power Doppler imaging, to velocity estimation. Our results show that the XDoppler estimator provides accurate measurements of axial velocities (RMSE=9.21%, R2=0.88) and outperforms the traditional phase-shift autocorrelator, while offering a theoretical Nyquist velocity twice as high. In vitro experiments further demonstrate enhanced sensitivity to slow flows (<10mm/s) and reduced bias in flow rate estimation. In vivo data from a carotid artery confirm the reduced sensitivity to aliasing and reveal the ability to track dynamic blood flow velocity changes associated with arterial pulsatility. These findings suggest that the proposed XDoppler estimator could improve volumetric blood velocity imaging with RCA probes.