MRI-based Protocol to Characterize the Relationship Between Bicuspid Aortic Valve Morphology and Hemodynamics

Area of Science:

• Cardiovascular Imaging
• Medical Engineering
• Biophysics

Background:

• Bicuspid aortic valve (BAV) is the most common congenital heart defect, often leading to serious cardiovascular complications like aortopathy.
• Predicting BAV-related aortopathy progression requires understanding aortic geometry and hemodynamics.
• Current assessment methods may lack standardization or efficiency for large-scale studies.

Purpose of the Study:

• To develop and validate a novel semi-automatic magnetic resonance imaging (MRI) protocol for characterizing aortic and aortic valve geometry and hemodynamics.
• To compare these parameters between individuals with BAV and healthy controls.
• To investigate the potential of these biomarkers in predicting disease progression using regression models.

Main Methods:

• A semi-automatic protocol using 2D cine and 4D flow MRI was developed.
• The protocol was applied to a cohort of 12 BAV patients and 12 control subjects.
• Statistical analyses, including group comparisons and linear regression, were performed to identify significant differences and associations.

Main Results:

• Significant differences were observed between BAV and control groups in orifice eccentricity, aorta diameter, velocity, jet angle, and flow displacement.
• In the ascending aorta, aorta diameter showed negative associations with mean velocity and positive associations with jet angle and flow displacement.
• A positive association was found between proximal aorta flow displacement and orifice jet angle in tricuspid aortic valve (TAV) subjects.

Conclusions:

• The developed MRI protocol enables standardized assessment of aortic geometry and hemodynamics in BAV disease.
• Identified geometric and hemodynamic differences highlight potential biomarkers for BAV-related aortopathy.
• The protocol's efficiency and limited user input make it suitable for large cohort studies investigating disease risk and progression.