CT angiography (CTA) uses the CT scanner to make pictures of the blood vessels of any part of the body. It has largely replaced the more invasive method of blood vessel imaging called conventional angiography.
CTA uses the CT scanner to make images of the body during intravenous contrast (X-ray dye) administration. An IV is started in the arm. X-ray dye is injected and a CT scan is made. By timing the scanning in relation to the contrast injection either the arteries of the veins can be highlighted. The computer then separates out the blood vessels that have contrast in them on every slice and places the contrast-enhanced blood vessel images on top of each other, like stacks of checkers, creating 3-dimensional images of the blood vessels.
CTA is useful to understand a vast number of conditions including:
CTA was developed in the 1990s and rapidly began to supplant conventional angiography, which had been in use for more than 70 years.
Conventional angiography generally required hospitalization and had risks that CTA does not have.
CTA is done in less than 20 minutes on an outpatient basis.
Because of its ease and flexibility, CTA has nearly completely eliminated conventional angiography for diagnostic purposes.