Healthy heart. Coloured arteriogram X-ray (or angiogram) showing in fine detail the coronary arteries of the heart. The outline of the heart is seen. Both left and right coronary arteries are visible here, branching to supply blood to the heart muscle. These arteries follow the rounded shape of the heart. An arteriogram is made by injecting the blood vessels of the patient with an X-ray opaque dye and then taking an X-ray. Blood vessels show up clearly, allowing conditions such as coronary artery disease (where the coronary arteries narrow) to be diagnosed. Blockages in either of these arteries that may lead to a heart attack may also be identified.