Angiography or arteriography is a medical imaging technique in which an X-ray image is taken to visualize the inside or (lumen) of blood vessles and organs of the body. With particular interest in the arteries, veins and the heart chambers. Depending on the type of angiogram, access to the blood vessels is gained most commonly through the femoral artery, to look at the left side of the heart and the arterial system or the Jugular or Femoral vein, to look at the right side of the heart and the venous system. Using a system of guide wires and catheters, a type of contrast agent is added to the blood to make it visible on the x-ray images.One of most common angiograms performed is to visualize the blood in the coronary arteries. A long, thin, flexible tube called a catheter is used to administer the x-ray contrast agent at the desired area to be visualized. The catheter is threaded into an artery in the groin or forearm, and the tip is advanced through the arterial system into one of the two major coronary arteries. X-ray images of the transient hiradiocontrast distribution within the blood flowing within the coronary arteries allows visualization of the size of the artery openings. Angiography is also commonly performed to identify vessel narrowing in patients with leg claudication or cramps, caused by reduced blood flow down the legs and to the feet; in patients with renal stenosis (which commonly causes high blood pressure) and can be used in the head to find and repair stroke.