CT Angiography (CTA) uses x-rays to view blood flow in blood vessels throughout the body, from arteries serving the brain to those bringing blood to the lungs, kidneys, arms, and legs. Beams of x-rays create cross-sectional images that are assembled by a computer into a three-dimensional picture of the area in question.
A CTA may be recommended for a variety of reasons. CTA helps visualize blood flow in the arteries that serve your kidneys, in patients with high blood pressure and those who are suspected of having kidney disorders. It's also used to identify life threatening aneurysms in the heart and brain. CTA also can help detect narrowing and blockages in the arteries.
CTA requires that you lie flat on your back. A rotating device then spins around your body creating a beam of x-rays. A detector takes snapshots of the beam after it passes through your body and a powerful computer program then processes the images and displays them in different ways for examination. The technician will communicate with you throughout the procedure, but will need to leave the room briefly to run the computer. A radiologist then reviews the images to look at the area in question. The scan will take about 5-10 minutes and the entire experience should last no more than 30 minutes.
Depending on what part of the body is being examined, you may receive a contrast injection. Contrast material is a dye that makes your organs and blood vessels more visible when you are scanned. If contrast is used, you will be asked not to eat or drink for four hours prior to the procedure. After the scan you should drink plenty of liquids to help flush the contrast out of your system.