High-Frame-Rate Doppler Ultrasound Using a Repeated Transmit Sequence

Area of Science:

• Medical Imaging
• Ultrasound Technology
• Biomedical Engineering

Background:

• High-frame-rate color flow Doppler ultrasound is crucial for visualizing blood flow.
• Coherent compounding techniques, while improving image quality, artificially reduce the effective frame rate, limiting maximum detectable velocity.

Purpose of the Study:

• To introduce and evaluate a novel transmit sequence for high-frame-rate ultrasound.
• To overcome the frame rate limitations imposed by coherent compounding in Doppler ultrasound.

Main Methods:

• A new transmit sequence was developed, repeating each transmit angle in succession.
• This sequence enables direct comparison of pre-compounded frames, mitigating sidelobe motion artifacts.
• Performance was assessed using a rotating phantom and a 15-MHz linear array transducer, measuring axial velocities up to ±300 mm/s.

Main Results:

• The new transmit sequence increased the maximum detectable velocity.
• Root mean square error in the high-velocity regime decreased from over 400 mm/s to below 50 mm/s.
• Standard deviation of velocity estimates reduced from 250 mm/s to 30 mm/s in the same velocity range.

Conclusions:

• The repeated transmit sequence method effectively enhances maximum detectable velocity in Doppler ultrasound.
• This technique demonstrates significant improvements in accuracy and precision for high-velocity flow quantification.
• The findings support the viability of this new method for advanced ultrasound applications.