Structural analysis and magnetic resonance imaging predict plaque vulnerability: a study comparing symptomatic and...

Area of Science:

• Biomedical Engineering
• Cardiovascular Research
• Medical Imaging

Background:

• Cerebral ischemic events frequently result from extracranial plaque rupture.
• Current clinical assessment relies on luminal stenosis, overlooking plaque morphology and biomechanics.
• Finite element analysis (FEA) offers a method to evaluate plaque vulnerability.

Purpose of the Study:

• To simulate and compare stress distributions within carotid plaques of symptomatic and asymptomatic individuals.
• To investigate the role of biomechanical stress in plaque rupture and clinical symptoms.
• To explore the potential of in vivo MRI-based FEA for stroke risk stratification.

Main Methods:

• High-resolution in vivo magnetic resonance imaging (MRI) of the carotid bifurcation in 30 subjects (15 symptomatic, 15 asymptomatic).
• FEA utilizing plaque geometry derived from MRI, modeling plaque components as hyperelastic.
• Comparison of peak stress concentrations between symptomatic and asymptomatic plaque groups.

Main Results:

• Significant stress concentrations identified at the shoulder regions of symptomatic plaques.
• Maximal predicted stresses were substantially higher in symptomatic plaques (508.2 kPa) compared to asymptomatic ones (269.6 kPa).
• The difference in maximal stresses between groups was statistically significant (P = .004).

Conclusions:

• Higher maximal plaque stresses in symptomatic patients suggest a link between stress and plaque rupture/symptoms.
• FEA of in vivo MRI data may serve as a valuable tool for assessing carotid atheroma risk.
• This approach could identify high-risk asymptomatic individuals and those with mild-to-moderate symptomatic stenoses.