ULTRAFAST DOPPLER IMAGING USING <i>P</i>TH ROOT FRAME-AND-SUM NONLINEAR COMPOUNDING BASED ON CLUTTER FILTERING BASEBAND CHANNEL DATA

Ultrafast Doppler imaging has broadened the application of ultrasound for clinical diagnosis and scientific research. Ultrafast imaging architectures with high-frame rate acquisition and highly parallel data processing have driven the development of microfluidic imaging. This study aimed to propose an ultrafast Doppler imaging method based on the pth root compression frame-and-sum (p-FAS) nonlinear compounding, employing clutter filtering of baseband channel data, aiming to improve the signal-to-noise ratio (SNR) of ultrafast Doppler images and provide both power and velocity Doppler images for better application in clinical ultrasound diagnosis. The method used multi-angle diverging-wave excitation. Also, clutter filtering was applied directly to the baseband channel data to obtain rich information on blood flow. The proposed p-FAS nonlinear compounding method based on signed pth root compressed angular frames emphasized the main-lobe blood flow information based on the spatial coherence between the diverging-wave angular frames and repressed the side-lobe clutter and grating artifacts. The performance of the proposed method was evaluated through an in vivo human renal study, and its contrast-to-noise ratio (CNR) and SNR were improved by the p-FAS-based method. This study demonstrated a complete ultrafast Doppler imaging link that provided power and velocity imaging, with higher SNR and microvascular visualization.