High resolution spectral micro-CT imaging of atherosclerotic plaque

Abstract

Spectral micro-Computed Tomography (CT) yields valuable quantitative information about elemental and molecular composition of materials. It enables the identification of materials by decomposing the total attenuation of the material into the various physical contributions for each voxel. Spectral micro-CT equipped with energy-resolved photon counting detector has the ability to measure the spectrum of x-ray beams. It is known that the attenuation of x-ray photons is energy-dependent and each substance has a specific attenuation curve. Therefore, measurement of the specific attenuation responses can enable material differentiation. The goal of this study was to demonstrate the potential of the MARS-CT scanner for preclinical evaluation of biomarker particularly in ex vivo advanced atherosclerotic plaque. It was proposed that spectral CT has the potential to identify the presence of specific markers for vulnerable plaques: iron deposits and lipid core. Using spectroscopic methods developed with this system, it was possible to distinguish the presence of iron deposits and lipid core within ex vivo atherosclerotic plaques. Vulnerable plaques are unstable, prone to rupture and put the person at risk of cardiovascular events and strokes. This preclinical study is a precursor to the development of a clinical technique that will enable vulnerable atherosclerotic plaques to be identified in vivo prior to treatment or removal.