An angiogram is an X-ray image of blood vessels after they are filled with a contrast material. An angiogram of the heart, a coronary angiogram, is the "gold standard" for the evaluation of coronary artery disease (CAD). A coronary angiogram can be used to identify the exact location and severity of CAD.

Coronary angiography is performed with the use of local anesthesia and intravenous sedation, and is generally not significantly uncomfortable.

• In performing a coronary angiogram, a doctor inserts a small catheter (a thin hollow tube with a diameter of 2-3 mm) through the skin into an artery in either the groin or the arm.
• Guided with the assistance of a fluoroscope (a special X-ray viewing instrument), 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 (a solution containing iodine, which is easily visualized with X-ray images) is injected into each coronary artery. The images that are produced are called the angiogram.
• The procedure takes approximately 20-30 minutes.
• After the procedure, the catheter is removed and the artery in the leg or arm is either sutured, "sealed," or treated with manual compression to prevent bleeding.
• Often, if an angioplasty orstent is indicated, it will be performed as part of the same procedure.

Angiographic images accurately reveal the extent and severity of all coronary artery blockages. For patients with severe angina or heart attack (myocardial infarction), or those who have markedly abnormal noninvasive tests for CAD (such as stress tests), the angiogram also helps the doctor select the optimal treatment. Treatments may then include medications, balloon angioplasty, coronary stenting, atherectomy ("roto-rooter"), or coronary artery bypass surgery.