A real time system for quantifying and displaying two-dimensional velocities using ultrasound

Area of Science:

• Medical imaging
• Ultrasound technology
• Biomedical engineering

Background:

• Current ultrasound Doppler instruments have limitations in displaying lateral motion and are prone to aliasing.
• Accurate real-time measurement of two-dimensional (2D) velocities is crucial for various diagnostic applications.

Purpose of the Study:

• To develop and validate a novel ultrasound system for real-time 2D velocity measurement.
• To overcome the limitations of existing Doppler techniques in terms of aliasing and lateral motion display.

Main Methods:

• A system was developed that tracks interframe speckle pattern motion using a Sum-Absolute-Difference (SAD) algorithm.
• A parallel architecture enables rapid calculation of velocity vectors, with a programmable graphics processor for real-time color encoding and display.
• The system was tested in vitro using flow phantoms.

Main Results:

• The system achieved real-time calculation of approximately 20,000 vectors per second.
• In vitro tests demonstrated tracking of velocities exceeding the Doppler aliasing limit in any scan plane direction with over 94% accuracy.
• The system successfully displayed lateral motion with uniform coloration, unlike conventional Doppler instruments.

Conclusions:

• The developed ultrasound system offers accurate and real-time measurement of 2D velocities.
• It provides superior visualization of flow dynamics, particularly lateral motion, compared to existing ultrasonic Doppler instruments.
• This technology has the potential to enhance diagnostic capabilities in ultrasound imaging.