The CAD-RADS grading scale is based on the degree of stenosis of the vessel lumen, which is generally graded in 6 levels. Coronary artery disease patients by doing coronary CT angiography, according to the degree of coronary artery stenosis, the different patients derived from the vascular grading situation. The details are as follows: Grade 0 indicates no plaque and stenosis, proving no CAD and unlikely to be ACS; Grade 1 indicates a degree of vessel lumen stenosis of 1-24% minimal stenosis, minimal with non-obstructive CAD and unlikely to be ACS; Grade 2 indicates a degree of vessel lumen stenosis of 25-49% mild stenosis, mild non-obstructive CAD and unlikely to be ACS. Grade 3 indicates a degree of luminal stenosis of 50 to 69% moderate stenosis, moderate stenosis, likely ACS; Grade 4 indicates a degree of luminal stenosis of 70 to 99%, with the terminology indicating A severe stenosis, B left main >50% or three vessels >70%, severe stenosis, likely ACS; Grade 5 indicates a degree of luminal stenosis of 100% complete obstruction, complete occlusion of the coronary artery, and a high likelihood of ACS. Grades 0, 1, and 2 generally do not require further cardiac function tests such as cardiac ultrasound. Grades 3, 4, and 5 require further examination and also require timely treatment measures. If you have chest pain timely consultation, under the guidance of the doctor active treatment, so as not to delay treatment.