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Updated: May 29, 2026
05:57
Blood Flow Imaging with Ultrafast Doppler
Published on: October 14, 2020
Effect of dual-frequency clutter suppression in harmonic Doppler detection
1Department of Electrical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan. Choushen@mail.ntust.edu.tw
Ultrasonics
|September 17, 2011
Summary
Third harmonic (3f(0)) transmit phasing suppresses tissue clutter in high-frequency Doppler imaging. This method enhances detection of low-velocity blood flow without reducing imaging speed.
Area of Science:
- Medical imaging
- Ultrasound technology
- Biomedical engineering
Background:
- High-frequency Doppler imaging offers potential for microcirculation blood flow detection.
- Spectral broadening of tissue clutter in swept-scan systems hinders low-velocity flow signal detectability.
- Conventional methods require reduced scanning speed, sacrificing imaging frame rate.
Purpose of the Study:
- To investigate an alternative method for clutter suppression in high-frequency Doppler imaging.
- To reduce interference to flow signals without compromising scanning speed.
- To improve the detectability of low-velocity flow.
Main Methods:
- Utilizing third harmonic (3f(0)) transmit phasing.
- Transmitting at fundamental and additional 3f(0) frequencies for mutual cancellation of second harmonic signal components.
- Reducing wall filter cut-off frequency to preserve low-velocity flow.
Main Results:
- Third harmonic (3f(0)) transmit phasing effectively reduces harmonic clutter magnitude.
- Improved flow signal-to-clutter ratio observed.
- Clutter-suppressed images demonstrate fewer artifacts and enhanced detection of low-velocity microbubble flow.
- Increased color-pixel-density in Doppler images.
Conclusions:
- Third harmonic (3f(0)) transmit phasing provides effective clutter suppression for swept-scan high-frequency (>20MHz) systems.
- The method enhances sensitivity for low-velocity flow detection at the same scanning speed.
- Resultant Doppler images are less susceptible to clutter artifacts.
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