Convex array vector velocity imaging using transverse oscillation and its optimization.

Area of Science:

• Ultrasound medical imaging
• Biomedical engineering
• Fluid dynamics

Background:

• Accurate blood flow estimation is crucial for diagnosing vascular diseases.
• Traditional ultrasound methods face limitations in quantifying complex flow patterns.
• Vector Flow Imaging (VFI) offers advanced capabilities for detailed flow analysis.

Purpose of the Study:

• To develop and validate an optimized transverse oscillation (TO) method for vector flow imaging using convex array probes.
• To improve the accuracy and reduce bias in estimating blood flow velocity.
• To assess the performance of the optimized TO method through simulations and experimental measurements.

Main Methods:

• Utilized a 3-MHz, 192-element convex array probe for simulations and measurements.
• Implemented an optimization routine to adjust the lateral oscillation period based on depth.
• Evaluated performance using simulated parabolic velocity profiles at various beam-to-flow angles and depths.
• Conducted in vivo scans on healthy volunteers' livers.

Main Results:

• Optimization reduced the energy ratio from -17.1 dB to -22.1 dB.
• Simulated data showed a decrease in standard deviation from 8.81% to 7.4% and bias from -15.93% to 0.78% at 90°.
• Experimental measurements yielded a bias of -0.93% and standard deviation of 6.37% at 87°.
• In vivo liver scans demonstrated realistic velocity estimates and consistent flow patterns.

Conclusions:

• The optimized TO method significantly enhances the accuracy of vector flow imaging with convex arrays.
• This technique provides reliable and precise blood flow velocity estimations in both simulated and in vivo settings.
• The improved VFI method holds promise for more accurate clinical diagnosis of vascular conditions.