Computed tomography (CT) uses X-rays to produce detailed images. In cardiac CT angiography, a non-invasive procedure, a dye injected into the blood provides contrast so that the heart muscle and surrounding blood vessels are better visible. A cardiac CT sometimes allows cardiologists to diagnose problems without using a more involved approach such as a cardiac catheter procedure. Another kind of cardiac CT is called calcium scoring. This more simple technique does not involve receiving contrast, and can be used to detect the presence and extent of plaque deposits in the heart’s blood vessels before they cause serious blockages.