Validation of 4D Flow based relative pressure maps in aortic flows

Area of Science:

• Cardiovascular Imaging
• Biomedical Engineering
• Fluid Dynamics

Background:

• Invasive catheterization is the gold standard for measuring pressure differences, but 4D Flow MRI offers a non-invasive alternative.
• Quantifying pressure differences non-invasively is crucial for diagnosing and managing cardiovascular conditions.

Purpose of the Study:

• To validate and compare pressure difference map estimators using 4D Flow MRI data.
• To assess the accuracy and robustness of the Stokes Estimator (STE) against the Pressure Poisson Estimator (PPE).

Main Methods:

• Comparison of STE and PPE with invasive catheter pressure measurements.
• Utilized 4D Flow MRI data from realistic aortic phantoms and patients with aortic coarctation.
• Investigated estimator sensitivity to resolution, segmentation, and noise using phantom data.

Main Results:

• The STE method demonstrated higher accuracy than the PPE method when compared to catheterization data.
• STE's superiority increased with higher Reynolds numbers, excelling in convective flow regimes.
• STE showed improved robustness against variations in lumen segmentation.

Conclusions:

• The STE is a more accurate and robust non-invasive method for pressure difference quantification using 4D Flow MRI.
• STE shows promise for clinical applications, particularly in conditions with complex hemodynamics.
• Further research may refine PPE for specific scenarios, but STE offers broader advantages.