MRI-based biomechanical imaging: initial study on early plaque progression and vessel remodeling

Area of Science:

• Biomedical Engineering
• Cardiovascular Research
• Medical Imaging

Background:

• Atherosclerosis involves complex biomechanical changes in arterial plaques.
• Noninvasive methods are needed to dynamically assess these biomechanical pathways in vivo.
• Existing techniques lack the resolution to capture subtle plaque alterations.

Purpose of the Study:

• To develop and validate a noninvasive magnetic resonance imaging (MRI)-based biomechanical imaging technique.
• To investigate the biomechanical pathways of atherosclerotic plaque progression and regression in vivo.
• To utilize a 3D fluid-structure interaction (FSI) model for calculating stress and strain distributions.

Main Methods:

• An in vivo pig model with induced carotid artery injury was used.
• Consecutive MRI scans were performed during plaque progression (high cholesterol) and regression (normal chow).
• A plaque-targeted contrast agent (Gadofluorine M) and dedicated mechanical testing were employed.

Main Results:

• Lower maximal flow shear stress correlated with plaque volume growth during progression.
• Maximal principal stress/strain (stress-P1, strain-P1) strongly correlated with plaque dimension changes during regression.
• Moderate correlation between maximal principal stress/strain and plaque dimension changes was observed during progression.

Conclusions:

• The developed MRI-based biomechanical imaging method enables noninvasive assessment of atherosclerotic plaque dynamics.
• This technique can provide insights into the role of local hemodynamic forces in plaque development and regression.
• The findings suggest potential for dynamic, in vivo monitoring of atherosclerosis progression and regression.