Number of CT plaque types among plaque-calcification-based pattern in vivo. The blue bars represent number of CT showed plaques base on PCP model. The red bars represent unstable atherosclerotic lesions of each type. There were statistical significance between them (all P<0.001). NCP-NRS indicates non-calcified plaque with napkin-ring-sign; NCP-none-NRS indicates non-calcified plaque without napkin-ring-sign; MP-DAS indicates mixed plaque with diamond-attenuation-sign; MP-none-DAS indicates mixed plaque without diamond-attenuation-sign; Ca-plaque indicates calcified plaque. PCP, plaque-calcification-pattern; NCP, non-calcified plaque; NRS, napkin-ring-sign; MP, mixed plaque; Ca-plaque, calcified plaque; DAS, diamond-attenuation sign.