angiography
n. the visualization of blood vessels by radiological techniques, used as an aid in diagnosing abnormalities or discovering blockages in areas of the circulatory system. For example, it can identify blood clots, tumors, aneurysms, and the degree of narrowing of the coronary arteries, which supply the heart. A dye opaque to X-rays is injected into a vessel and any disruption of blood flow is revealed as a contrasting pattern. When the imaging is of arteries, it is also called arteriography. The image produced is called an angiogram (or arteriogram). See also cerebral angiography; digital subtraction angiography.