Angiography is a type of medical imaging that uses x-rays and a contrast agent to produce images of blood vessels.
In angiography, x-rays are used to produce detailed images of blood vessels. It is sometimes called conventional angiography to distinguish it from computed tomography (CT) angiography and magnetic resonance angiography (MRA). During angiography, doctors can also treat disorders of blood vessels. Angiography, although invasive, is relatively safe.
Angiography can provide still images or motion pictures (called cineangiography). Cineangiography can show how fast blood travels through blood vessels. (See also Coronary Angiography and Overview of Imaging Tests .)
Before the angiography procedure, people are usually asked to refrain from eating and drinking for 12 hours.
For the procedure, people lie on an x-ray table (one that x-rays can easily pass through). Because the table may be tilted, straps may be applied across the chest and legs. X-ray cameras can be positioned as needed. Electrodes are placed on the chest to monitor the heart. Blood pressure and oxygen levels are also monitored.
After injecting a local anesthetic, a doctor makes a small incision, typically in the groin or sometimes in the arm. Then a thin, flexible tube (catheter) is inserted, usually into an artery, and is threaded through blood vessels to the area being evaluated. When the catheter is in place, a radiopaque contrast agent (a liquid that contains iodine and can be seen on x-rays) is injected. The contrast agent flows through the blood vessels and outlines them. The images appear on a video screen and are recorded. Thus, doctors can assess the structure of blood vessels and identify any abnormalities present.
Before angiography, people are often given a sedative intravenously to help them relax and remain calm, but they remain conscious during the procedure. During the procedure, people may be asked to take deep breaths, hold their breath, or cough. People should report any discomfort they feel.
Angiography may take less than an hour or several hours, depending on the area of the body being evaluated and the type of the examination or procedures being done. It is usually done as an outpatient procedure.
If the catheter is inserted into an artery, the insertion site must be steadily compressed for 10 to 20 minutes after all the instruments are removed. Compression reduces bleeding and bruises.