Dyeless angiography

Dyeless angiography

Angiography or imaging of blood vessels usually require injection of a radiocontrast (dye) into the blood vessels and imaging them with X-ray technology. Dyeless angiography is possible with magnetic resonance imaging where the signals from the moving hydrogen particles in blood give the image. This is known as magnetic resonance angiography. This avoids the risk of radiocontrast dyes which could produce adverse effects like allergic reaction, kidney dysfunction, transient suppression of cardiac function producing fall in blood pressure etc.

Another form of dyeless angiography is carbon dioxide angiography in which gaseous carbon dioxide is injected in the blood vessel, typically into the renal artery for renal angiography. This produces a negative contrast compared to usual radiocontrasts. Carbon dioxide gets rapidly absorbed into the blood and there is no adverse effect, though the visualisation is not as good as other radiocontrast agents.