Inclusion Criteria:  Age ≥ 18 years old Type 2 diabetes is diagnosed according to WHO diagnostic criteria Low dose prospectively triggered sequential dual-source CT coronary angiography can be performed at baseline investigation Those subjects are able to understand the purpose and procedure of this study and sign the informed consent voluntarily  Exclusion Criteria:  Those have received coronary artery stenting or coronary artery bypass grafting Those with severe lung (respiratory failure), liver (ALT or AST 3 times normal value or bilirubin increase), renal dysfunction[GFR < 45ml/(min.1.73m2) or dialysis patients Malignant tumor Mental illness or mental retardation Pregnant or lactating women or those with fertility planning Concomitant diseases (hyperparathyroidism, sarcoidosis, amyloidosis) affecting calcium balance and soft tissue calcification Contraindications of contrast agents Based on the judgment of the researcher, the compliance is poor and the study could not be completed according to the requirements