An LDV based method to quantify the error of PC-MRI derived Wall Shear Stress measurement

Area of Science:

• Biomedical Engineering
• Cardiovascular Imaging
• Fluid Dynamics

Background:

• Wall Shear Stress (WSS) is a critical biomarker in atherosclerosis development.
• In vivo WSS assessment is challenging; 4D Flow MRI offers potential for calculating WSS from 3D velocity data.

Purpose of the Study:

• To validate 4D Flow MRI acquisitions and Wall Shear Stress (WSS) computation methods using Laser Doppler Velocimetry (LDV).
• To compare the performance of 2D and 3D Wall Shear Stress (WSS) calculation methods.
• To investigate the impact of spatial resolution and noise on 3D Wall Shear Stress (WSS) assessment.

Main Methods:

• Development of a hydraulic circuit for simultaneous 4D Flow MRI and Laser Doppler Velocimetry (LDV) measurements.
• Calculation of Wall Shear Stress (WSS) profiles using one 2D and one 3D computational method.
• Evaluation of the influence of spatial resolution on derived 3D Wall Shear Stress (WSS) profiles.

Main Results:

• Excellent agreement was observed between 4D Flow MRI and Laser Doppler Velocimetry (LDV) velocity data.
• The study confirmed the superior performance of the 3D Wall Shear Stress (WSS) computation method over the 2D method.
• Refined spatial resolution in 4D Flow MRI did not improve Wall Shear Stress (WSS) assessment when noise impact was not reduced, even with clinically compatible acquisition times.

Conclusions:

• The developed Laser Doppler Velocimetry (LDV) system provides a reliable platform for validating 4D Flow MRI-based Wall Shear Stress (WSS) calculation methods.
• This validation is crucial for advancing the clinical application of 4D Flow MRI in cardiovascular research.
• Optimizing MRI acquisition parameters, including noise reduction, is essential for accurate Wall Shear Stress (WSS) quantification.