Atherosclerotic plaque imaging using phase-contrast X-ray computed tomography.

Area of Science:

• Medical Imaging
• Biophysics
• Cardiovascular Research

Background:

• Noninvasive characterization of coronary plaque components is crucial for identifying unstable plaques causing acute coronary syndrome.
• Computed tomography (CT) struggles to identify noncalcified plaque components, limiting its diagnostic capabilities.
• Phase-contrast X-ray CT offers superior sensitivity to light elements and tissue mass density estimation compared to absorption-contrast X-ray imaging.

Purpose of the Study:

• To investigate the potential of ex vivo phase-contrast X-ray CT for characterizing atherosclerotic plaque components.
• To assess the ability of phase-contrast X-ray CT to estimate specific mass densities of plaque constituents.
• To evaluate phase-contrast X-ray CT as a noninvasive tool for detecting unstable coronary plaques.

Main Methods:

• Ex vivo phase-contrast X-ray CT performed on atherosclerotic plaques from apolipoprotein E-deficient mice using synchrotron radiation.
• Histological analysis of plaque samples for comparison and validation.
• Quantitative estimation of specific mass densities for different plaque components.

Main Results:

• Phase-contrast X-ray CT at 10-20 mum resolution clearly visualized atherosclerotic plaque components, including thin fibrous caps.
• Specific mass densities were quantitatively estimated, with lipid areas showing significantly lower density (1.011 g/ml) than smooth muscle (1.057 g/ml) or collagen (1.080 g/ml).
• Three-dimensional assessment provided anatomical information of the plaques.

Conclusions:

• Phase-contrast X-ray CT is a promising noninvasive technique for investigating atherosclerotic plaque components.
• The method can accurately estimate tissue mass density, enabling the detection of lipid-rich areas indicative of unstable plaques.
• This imaging modality holds potential for improved diagnosis and management of coronary artery disease.