Angiography

Angiography, technique allowing visualization of blood vessels on X rays after injection of a radiopaque substance (one that shows up on X ray). It is usually performed on arteries or veins connected with organs such as the brain, heart, or kidneys, when a narrowing or blockage is suspected. Angiography is used to determine if deposits of substances such as cholesterol or calcium, known as plaque, are causing vessel narrowing, and has developed into a relatively safe and useful diagnostic technique. A typical angiographic procedure involves the passing of a catheter through the skin and into a vein or artery, where it is advanced to the structure being evaluated. Contrast material is injected into the area, making the section visible on X ray.