In patients with coronary artery disease, acute coronary syndromes can account for up to 70% of deaths.  The progression of an asymptomatic fibroatheromatous plaque into a vulnerable plaque is often poorly diagnosed and not generally well understood.  In many instances, the lesions responsible for acute coronary syndromes are not flow-limiting on coronary angiography and, as a result, current imaging technologies are not able to sufficiently identify patients at greatest risk for future acute coronary syndromes. 
Higher resolution requirements for coronary imaging have driven the development of catheter based technologies, which can permit examination of physical features of vulnerable plaques, such as plaque morphology (large necrotic core and thin fibrous cap, using optical coherence tomography and intravascular ultrasound (IVUS)), mechanical properties (palpography and intravascular elastography using IVUS), composition (Virtual histology), or lipid content (near-infrared spectroscopy).  However, conventional approaches for coronary imaging have significant shortcomings and improvements to the current capabilities in detecting vulnerable plaque and understanding plaque progression in the coronaries is desirable.