Ultrasound Power Doppler Imaging Using Regional-Lag Signed Delay Multiply and Sum Beamformer

Ultrasound power Doppler imaging serves as an essential diagnostic modality for blood flow visualization in clinical practice, demonstrating superior sensitivity relative to conventional color Doppler imaging. Despite its advantages, further enhancement in imaging quality remains imperative to achieve more precise clinical diagnoses. This study introduces an innovative power Doppler imaging technique incorporating a regional-lag signed delay multiply and sum (rsDMAS) beamformer to improve contrast performance. The proposed rsDMAS algorithm overcomes existing technical limitations through dynamic optimization of the maximum lag parameter for coherence estimation, effectively amplifying blood flow signals while maintaining the integrity of weaker vascular signals. Furthermore, the implementation of a clutter filter on aperture-compounded signals successfully addresses phase distortion artifacts that would otherwise compromise imaging quality. Comprehensive validation through both simulation and in vivo experiments revealed substantial performance improvements: contrast ratio (CR) enhancements of 39 and 10.7%, contrast-to-noise ratio (CNR) improvements of 9 and 55.8%, and signal-to-noise ratio (SNR) gains of 40 and 7.8% compared to frame multiply and sum (FMAS) and delay multiply and sum (DMAS) methods, respectively. The developed technique demonstrates robust suppression of thermal noise and acoustic clutter, ultimately yielding significantly enhanced blood flow imaging capabilities for clinical applications.