An angiogram is a diagnostic test that uses x-rays to take pictures of your blood vessels. A long flexible catheter is inserted through the bloodstream to deliver dye (contrast agent) into the arteries making them visible on the x-ray. A coronary angiogram is a procedure that uses X-ray imaging to see your heart's blood vessels. The test is generally done to see if there's a restriction in blood flow going to the heart. Coronary angiograms are part of a general group of procedures known as heart (cardiac) catheterizations. Cardiac catheterization procedures can both diagnose and treat heart and blood vessel conditions. A coronary angiogram, which can help diagnose heart conditions, is the most common type of cardiac catheterization procedure.