Coronary angiography is a method of inserting a catheter from the femoral artery at the root of the thigh or the flexural artery at the wrist, passing through the aorta to the opening of the left and right coronary arteries, injecting contrast, and showing the morphology of the coronary arteries under x-ray fluoroscopy. It is a direct method to diagnose coronary artery disease as it can clearly show the coronary artery course and the area of narrowing or blockage of blood vessels due to atherosclerosis.