Cardiac Calcium Scoring CT: A fast and non-invasive study used to screen for significant heart disease. Your doctor may order this test if you have symptoms or risk factors for heart disease. This test takes about 5 minutes and quantifies the amount of calcium in the walls of the coronary arteries, the arteries supplying the heart. The more calcium, the higher the risk for heart disease. The report that you and your doctor receive will provide a detailed interpretation of your calcium score.