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Spatial-angular baseband delay multiply and sum beamforming with coherence factor for 3D power Doppler imaging
Zhiqiang Li1, Zucheng Zhang1, Jianwen Luo1
1School of Biomedical Engineering, Tsinghua Medicine, Tsinghua University, Beijing 100084, China.
Ultrasonics
|August 4, 2026
Summary
New beamforming methods, spatial-angular baseband delay multiply and sum (SA-DMAS) and SA-DMAS-CF, significantly enhance three-dimensional power Doppler imaging (3D PDI) quality. These techniques improve microvascular visualization and reduce noise in medical imaging.
Area of Science:
- Medical Imaging
- Ultrasound Technology
- Biomedical Engineering
Background:
- Three-dimensional power Doppler imaging (3D PDI) using matrix arrays is limited by small effective apertures and low element sensitivity.
- Existing methods struggle to provide high-quality volumetric visualization of microvascular networks.
Purpose of the Study:
- To introduce and evaluate novel beamforming techniques, spatial-angular baseband delay multiply and sum (SA-DMAS) and its coherence-weighted version (SA-DMAS-CF), for improving 3D PDI quality.
- To enhance spatial resolution, vessel-to-background separability, and weak blood flow visualization in 3D PDI.
Main Methods:
- Development of SA-DMAS beamforming, integrating delayed channel data from multiple plane wave transmissions.
- Implementation of SA-DMAS-CF with voxel-wise coherence weighting to suppress incoherent components.
- Evaluation using simulations (point targets, microtubes), phantom experiments, and in vivo 3D PDI (rat/mouse brain, rat kidney).
Main Results:
- SA-DMAS-CF demonstrated superior performance with the smallest FWHM (0.181 mm) and lowest SLL (-84.97 dB) in simulations.
- Highest contrast-to-noise ratios (CNRs) were achieved by SA-DMAS-CF in simulations, phantom, and in vivo experiments (e.g., 37.81 dB in rat brain).
- Significant improvements in spatial resolution, vessel-to-background separability, and weak flow visualization were observed compared to DAS.
Conclusions:
- SA-DMAS-CF beamforming effectively overcomes limitations of matrix array-based 3D PDI.
- The proposed methods offer substantial improvements in image quality for visualizing microvascular networks.
- SA-DMAS-CF is a promising technique for advanced 3D PDI applications in preclinical and clinical settings.
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