StaBle: Staggered PRF With DouBle Transmission for Increasing the Velocity Limit of High-Frame-Rate Vector Doppler...

Area of Science:

• Medical imaging
• Ultrasound technology
• Biomedical engineering

Background:

• Vector Doppler Imaging (VDI) measures blood flow in multiple directions but is limited by aliasing artifacts.
• Aliasing is prevalent in high-frequency applications like small animal cardiac imaging, exacerbated by multiple transmit angles.
• Existing VDI methods struggle to accurately measure high velocities without aliasing.

Purpose of the Study:

• To introduce and evaluate a novel transmission scheme, StaBle, for Vector Doppler Imaging.
• To significantly increase the velocity limit of conventional VDI and mitigate aliasing.
• To demonstrate the efficacy of StaBle in small animal cardiac applications.

Main Methods:

• StaBle combines staggered multiple pulse repetition frequency (PRF) with a double transmission scheme.
• The method utilizes three transmit angles and two PRFs to extend the velocity limit.
• Performance was evaluated using simulations and phantom spinning disk experiments, including in vivo mouse left ventricle imaging.

Main Results:

• StaBle achieved a 6-12 times higher velocity limit compared to sequential angle VDI.
• Simulations showed a normalized root-mean-squared error of less than 5% for axial and lateral velocity estimation.
• Phantom experiments demonstrated a 9-fold improvement in peak axial velocity detection.
• In vivo imaging successfully resolved aliased vector fields in a mouse left ventricle.

Conclusions:

• StaBle effectively increases the velocity limit and reduces aliasing in Vector Doppler Imaging.
• The proposed method shows robustness and potential for investigative studies in small animal cardiac applications.
• StaBle offers a significant advancement for accurate blood flow measurement in challenging ultrasound scenarios.