High Frame Rate Ultrasound: Zooming into the Time Axis for Complex Flow Visualization
* Presenting author
With the advent of spectral Doppler and color flow imaging (CFI), ultrasound has been clinically assisting numerous vascular diagnoses in the past 30 years. However, spectral Doppler can only render such information at a single range gate, while CFI is known to be susceptible to numerous sources of estimation errors that hamper flow visualization quality, especially in complex flow situations. To overcome these limitations, our group has successfully harnessed the time-resolving power of high frame rate ultrasound (HiFRUS) to dynamically render complex flow dynamics over an imaging view at millisecond time resolution. Our HiFRUS technique, dubbed as vector projectile imaging (VPI), is capable of estimating flow vectors from multi-angle Doppler analysis and rendering these vector estimates as moving color-encoded projectiles. In a series of bifurcation phantom studies, VPI has vividly highlighted the flow jet emerging from the stenosis site and its trajectory. Also, it has enabled time-resolved observation of multiple flow disturbance zones. Moreover, in vivo investigations using VPI has revealed unique flow features in the carotid bifurcation of subjects who are experiencing lower-body negative pressure conditions. Taken together, VPI is poised to become a useful tool for obtaining new hemodynamic insights that are important to human physiology investigations.