Parallel Receive Beamforming Improves the Performance of Focused Transmit-Based Single-Track Location Shear Wave...

Area of Science:

• Medical Imaging
• Ultrasound Elastography
• Biomedical Engineering

Background:

• Single-track location shear wave elastography (STL-SWEI) is susceptible to electronic noise, increasing shear wave speed (SWS) estimate variance.
• Current parallel beamforming techniques for noise reduction often utilize broad transmit beams, which are less common in clinical ultrasound systems.
• Clinical ultrasound systems typically use focused transmit beams, necessitating improved noise robustness for STL-SWEI in these settings.

Purpose of the Study:

• To experimentally evaluate the performance of parallel beamforming for STL-SWEI using focused transmit beams.
• To assess the impact of fixed and multiple transmit focus strategies on elastographic signal-to-noise ratio (SNR_e).
• To determine optimal parallel beamforming parameters for noise suppression in focused transmit-based STL-SWEI.

Main Methods:

• Implementation and experimental evaluation of parallel beamforming for STL-SWEI with fixed and multiple transmit foci.
• Imaging of tissue-mimicking phantoms to quantify SNR_e improvements.
• Analysis of SNR_e variations based on receive line spacing, parallel line count, and tracking focal zone depth.

Main Results:

• Parallel beamforming improved focal zone SNR_e by 40.9% using focused transmit beams.
• Optimal parallel line averaging varied with depth; 3 lines for the focal zone and >7 for shallower regions (<20 mm).
• Increasing beamforming line density yielded diminishing returns in SNR_e, and multifocusing strategies were less effective than single-focus configurations.

Conclusions:

• STL-SWEI can be effectively implemented with focused transmit beams using parallel beamforming for robust noise suppression.
• The findings support the potential for easier clinical translation of STL-SWEI.
• Depth-dependent averaging strategies can optimize noise reduction for focused transmit beams.