Collagen characterization by polarized and acoustic microscopy

Rupture of the fibrous cap overlying a soft lipid pool in atherosclerotic plaque is the trigger for acute coronary syndrome. As collagen is the main component of the fibrous cap, determination of its mechanical properties is important. In this regard, the feasibility of scanning acoustic microscopy and polarized microscopy was studied using treated aortic root samples from Apo-E deficient and normal mice. Very high frequency ultrasound of the SAM could provide information of collagen type without staining, while lower frequency intravascular ultrasound offer some possibilities. As ultrasound features correlate closely with the material mechanical properties, the imaging modality may be used to evaluate the stability of atherosclerotic plaques.