Determining Haemodynamic Wall Shear Stress in the Rabbit Aorta In Vivo Using Contrast-Enhanced Ultrasound Image...

Area of Science:

• Biomedical Engineering
• Cardiovascular Physiology
• Medical Imaging

Background:

• Abnormal blood flow and wall shear stress (WSS) are linked to cardiovascular diseases.
• Current methods for in vivo WSS mapping lack standardization.

Purpose of the Study:

• To demonstrate a wide-field assessment of WSS in the rabbit abdominal aorta using contrast-enhanced ultrasound image velocimetry (UIV).
• To validate the accuracy and reliability of UIV for WSS measurements in a large field of view.

Main Methods:

• Utilized contrast-enhanced ultrasound image velocimetry (UIV) for flow and WSS measurements in the rabbit abdominal aorta.
• Validated measurements using an in silico model with pulsatile flow and moving walls.
• Compared UIV WSS measurements with an analytic approximation derived from the Poiseuille equation.

Main Results:

• Achieved high accuracy in velocity (0.34% mean error) and WSS (1.69% mean error) measurements over a cardiac cycle.
• Demonstrated high correlation (PC=0.99) between in vivo and simulated WSS in the suprarenal aorta.
• Mapped WSS in arterial branching regions, observing high time-average WSS and oscillatory flow.

Conclusions:

• Contrast-enhanced UIV provides an accurate, wide-field method for measuring in vivo WSS.
• This technique can capture spatiotemporal variations in flow velocity and arterial wall dynamics.
• UIV holds promise for advancing cardiovascular disease research and diagnosis.