This document discusses various methods for identifying vulnerable plaques, including non-invasive imaging techniques like CT and MRI, as well as invasive techniques like intravascular ultrasound (IVUS) and optical coherence tomography (OCT). It summarizes several studies that examined autopsy specimens to determine the prevalence of thin-capped fibroatheromas and disrupted plaques. The document also describes the goals of using advanced IVUS spectral analysis to characterize plaque composition in vivo and a potential natural history study to determine if detecting vulnerable plaque can predict future cardiovascular events.