Image:Angiogram WHO 933.jpg
Angiography or arteriography is a medical imagingtechnique in which an X-raypicture is taken to visualize the inner opening of blood filled structures, including arteries, veinsand the heart chambers. Its name comes from the Greekwords angeion, "vessel", and graphien, "to write or record". The X-ray film or image of the blood vesselsis called an angiograph, or more commonly, an angiogram.
The Portuguesephysician and neurologist Egas Moniz, Nobel Prizewinner in 1949, developed in 1927the technique of contrasted x-ray cerebral angiographyto diagnose several kinds of nervous diseases, such as tumors and arteriovenous malformations. He is usually recognised as one of the pioneers in this field. With the introduction of the Seldinger techniquein 1953, the procedure became markedly safer as no sharp introductory devices needed to remain inside the vascular lumen.
Angiograms require the insertion of a catheterinto a peripheral artery, e.g. the femoral artery.
As blood has the same radiodensityas the surrounding tissues, a radiocontrastagent (which absorbs X-rays) is added to the blood to make angiography visualization possible. The angiographic X-Ray image is actually a shadow picture of the openings within the cardiovascular structures carrying blood (actually the radiocontrast agent within). The blood vessels or heart chambers themselves remain largely to totally invisible on the X-Ray image.
The X-rayimages may be taken as either still images, displayed on a fluoroscopeor film, useful for mapping an area. Alternatively, they may be motion images, usually taken at 30 frames per second, which also show the speed of blood (actually the speed of radiocontrast within the blood) traveling within the blood vessel.
The most common angiogram performed is to visualize the blood in the coronary arteries. A long, thin, flexible tube called a catheteris used so as to administer the radiocontrast agent at the desired area to be visualized. The catheter is threaded into an artery in the groinor forearm, and the tip is advanced through the arterial system into one of the two major coronary arteries. X-rayimages of the transient radiocontrastdistribution within the blood flowing within the coronary arteries allows visualization of the size of the artery openings. Presence or absence of atherosclerosisor atheromawithin the walls of the arteriescannot be clearly determined. See coronary catheterizationfor more detail.
Angiography is also commonly performed to identify vessel narrowingin patients with retinalvascular disorders, such as diabetic retinopathyand macular degeneration.
Types of angiographs
- Cerebral angiography
- Coronary angiography
- Extremity angiography(arm or leg)
- Renal angiography(kidneys)
- Pulmonary angiography(lungs)
- Lymphangiography(lymph vessels)
- Right heart ventriculography(looking at the right side of the heart)
- Left heart ventriculography(looking at the left side of the heart)
- Aortography(looking at the aorta, the major artery from the heart)
- Retinal angiography
The term angiography, or angeiography, was originally used of a description of the weights, measures, vessels, etc, used by several nations.
- Angiography Equipmentfrom Siemens Medical
- Cardiovascular and Interventional Radiological Society of Europede:Angiografie
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It uses material from the http://en.wikipedia.org/wiki/Angiogram Wikipedia article Angiogram.