Acute coronary syndrome often leads to severe cardiovascular events, and the cause of most acute coronary syndromes is coronary atherosclerotic plaque rupture. Therefore, the detection of vulnerable plaque with high risk of rupture is of great significance for the screening and intervention of acute coronary syndrome. Vulnerable plaques have some microstructures such as neovascularization, spotty calcification and cholesterol crystal, which play important roles in the progression and pathogenesis of vulnerable plaques.