The most accurate method for evaluating and defining coronary artery disease (CAD). Coronary angiography is used to identify the exact location and severity of CAD. During coronary angiography, a small catheter is inserted through the skin into an artery in the groin or the arm. Guided with the assistance of a fluoroscope, the catheter is then advanced to the opening of the coronary arteries, the blood vessels supplying blood to the heart. Next, a small amount of radiographic contrast is injected into each coronary artery.