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Updated: Jul 19, 2025
09:36
Continuous-Wave Propagation Channel-Sounding Measurement System - Testing, Verification, and Measurements
Published on: June 25, 2021
3.1K
Robust Imaging of Speed of Sound Using Virtual Source Transmission
Summary
Virtual-source (VS) transmit sequences improve signal-to-noise ratio (SNR) and motion robustness in speed of sound (SoS) imaging. VS sequences offer superior SoS reconstruction performance for soft tissue biomechanics assessment in clinical ultrasound.
Area of Science:
- Biomedical Ultrasound
- Medical Imaging
- Biophysics
Background:
- Speed of sound (SoS) imaging offers novel insights into soft tissue biomechanics.
- Conventional ultrasound (US) systems with single-element (SE) diverging wave (DW) transmissions have limitations in signal-to-noise ratio (SNR).
- Existing SoS imaging methods can be confounded by beamforming inaccuracies, especially in the presence of motion.
Purpose of the Study:
- To develop and evaluate novel transmit sequences for enhanced SNR in SoS imaging.
- To introduce an iterative method for accurate beamforming (BF) SoS estimation.
- To assess the performance and motion robustness of proposed sequences against conventional methods.
Main Methods:
- Implementation of Walsh-Hadamard (WH) coded and virtual-source (VS) transmit sequences.
- Development of an iterative beamforming SoS estimation technique.
- Validation through numerical simulations, phantom experiments, and in vivo clinical data.
Main Results:
- WH sequences demonstrated poor robustness to motion artifacts, significantly increasing SoS root-mean-square error (RMSE).
- VS sequences exhibited superior SoS reconstruction performance and were highly robust to motion.
- In phantom studies, VS showed comparable resting RMSE to SE but maintained performance under motion, unlike WH.
- Clinical data revealed higher SNR and contrast with VS sequences compared to SE and WH.
Conclusions:
- Virtual-source (VS) transmit sequences represent a significant advancement for motion-robust and high-SNR speed of sound imaging.
- The proposed iterative beamforming method improves SoS reconstruction accuracy.
- VS sequences hold great potential for improved clinical assessment of soft tissue biomechanical properties.
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