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Two-Dimensional Wavenumber Analysis Implemented in Ultrasonic Vector Doppler Method with Focused Transmit Beams
Hideyuki Hasegawa1, Masaaki Omura1, Ryo Nagaoka1
1Faculty of Engineering, University of Toyama, Toyama 930-8555, Japan.
Sensors (Basel, Switzerland)
|December 23, 2022
Summary
This study enhances ultrasound velocity vector estimation by applying two-dimensional wavenumber analysis to focused beams. This method achieves comparable accuracy to plane wave imaging while improving B-mode image contrast in specific applications.
Area of Science:
- Ultrasound imaging
- Medical diagnostics
- Biomedical engineering
Background:
- Multi-angle Doppler methods estimate velocity vectors by measuring axial velocities from multiple directions.
- Autocorrelation-based velocity vector estimation can be improved by two-dimensional (2D) wavenumber estimation.
- Previous 2D wavenumber estimation utilized plane wave imaging, which offers high temporal resolution but lower B-mode contrast compared to focused beams.
Purpose of the Study:
- To implement and evaluate 2D wavenumber analysis within a focused transmit beam framework for ultrasound velocity vector estimation.
- To compare the performance of 2D wavenumber analysis using focused beams versus plane wave imaging in terms of velocity estimation accuracy and B-mode image contrast.
- To assess the clinical applicability by in vivo measurements of human common carotid arteries.
Main Methods:
- Implementation of 2D wavenumber analysis in a focused beam ultrasound imaging system.
- Simulation studies to assess velocity estimation accuracy compared to plane wave imaging.
- In vivo experiments on human common carotid arteries to evaluate B-mode image contrast (normal and clutter-filtered) and velocity estimation parameters.
Main Results:
- Simulations demonstrated that the focused beam method achieved velocity estimation accuracy comparable to plane wave imaging.
- In vivo results showed focused beam imaging yielded better contrast in normal B-mode images.
- Both focused beam and plane wave imaging methods provided similar velocity magnitudes and angles, but plane wave imaging offered better contrast in clutter-filtered B-mode images and lower velocity magnitude variances.
Conclusions:
- Two-dimensional wavenumber analysis can be effectively implemented with focused transmit beams for ultrasound velocity vector estimation.
- The focused beam approach offers advantages in B-mode image contrast for certain applications compared to plane wave imaging.
- Both focused beam and plane wave imaging methods provide reliable velocity measurements, with trade-offs in image contrast and velocity variance depending on the imaging mode and filtering.
Keywords:
autocorrelation techniquebeam steering angleblood flow measurementcenter frequencyvector DopplerMore Related Videos
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