Computed Tomography Angiography (CTA)

CTA creates images of arteries throughout the body. A contrast medium (x-ray dye) is injected to make the blood vessels stand out. Pictures are then taken with the CT scanner. The CT images are processed by a computer to make a three-dimensional picture.

Why CTA Is Done

CTA may be used to:

• Examine arteries in the abdomen, neck, lungs, pelvis, kidneys, or brain.

• Look for an aneurysm (ballooning of the blood vessel wall) or dissection (tear).

• See whether a stent (device used to keep an artery open) is working properly.

• Detect damage to arteries due to injuries.

• Gather details on blood vessels that supply tumors.

Preparing for the Procedure

• Drink only clear liquids for 6 hours before the procedure.

• Tell your radiologist what medications, herbs, or supplements you take; if you are, or may be, pregnant; or if you are allergic to contrast medium or other medications.

• Remove hair clips, jewelry, dentures, and other metal items that could show up on the x-ray.

During the Procedure

• You'll lie down on the scanning table. An IV (intravenous) line will be set up.

• The scanning table will be positioned so that the part of your body being examined is inside the donut-shaped CT scanner.

• One image may be taken to be sure you are positioned correctly for the test.

• The IV will be hooked up to an automatic injection machine. This controls the timing and rate of injection. The injection may continue during part of the exam.

• Contrast medium will be injected into a vein through the IV line. You may feel warmth through your body when the contrast material is injected.

• You will need to remain still while the x-rays are being taken. Pillow and foam pads may be used to help you stay in position. You'll be told to hold your breath for 10 to 25 seconds at a time.

• The whole procedure may take 10 to 25 minutes.

After the Procedure

• Drink plenty of fluids to help flush the contrast fluid from your system.

• You may eat as soon as you wish to.