Cardiac magnetic resonance is a means of evaluating coronary artery disease, but is not to be used as the gold standard for the diagnosis of coronary artery disease. The gold standard for the diagnosis of coronary artery disease is usually made by coronary angiography and coronary CT scanning for the presence of coronary artery stenosis. Cardiac MRI is used as a means of evaluation, using a resting first-pass perfusion scan sequence, and a contrast delayed scan sequence. If perfusion defects, and areas of reduced perfusion are found on the resting perfusion scan, it is generally determined that the coronary arteries have severe stenosis. Contrast-delayed enhancement, i.e., delayed enhancement foci, can clearly distinguish the area of myocardial necrosis, but delayed enhancement foci, there are two significant features: 1, delayed enhancement foci, from the endocardium occurs gradually to the epicardium expansion; 2, the area of cardiac necrosis, and the distribution of the coronary arteries exactly match the area. These characteristics can be used as a means of clinical judgment of coronary artery disease, and now cardiac magnetic resonance has become a powerful means of evaluating the prognosis of coronary artery disease and judging the area of myocardial necrosis in clinical practice.