CT Brain Angiography:what to expect

Your doctor may request a CTA Brain for:

• Acute, sudden onset of a severe headache (often called a "thunderclap" headache).
• Suspected subarachnoid hemorrhage (bleeding in the space around the brain).
• Symptoms of an acute stroke (such as sudden weakness, confusion, or difficulty speaking).
• A personal or family history of brain aneurysms.
• Suspected venous thrombosis (a blood clot in the brain's veins).

A CTA is a specific test, but it is frequently combined with a CTA of the neck to give doctors a complete view of the blood flow from your heart up to your brain.

The scan itself does not usually hurt. You may feel the IV placement and a brief warm flush or metallic taste. Report injection-site pain or swelling, hives, breathing difficulty, or faintness immediately.

In emergency situations, no preparation is done. For scheduled scans, you may be asked to fast for a few hours. You should also let the care team know if you have any history of kidney problems or contrast allergies.

If your scan is scheduled, you might be asked to avoid solid foods for a few hours before the test. Clear liquids are usually permitted.

You will be asked to remove earrings, hearing aids, hairpins, and removable dental appliances so they do not interfere with the images.

The CT scanner is shaped like a wide, circular ring. You lie on a narrow table that gently moves your head into the center while images are captured.

You will lie flat on your back with your head resting in a special holder to keep it still. An IV line will be placed in your arm or hand to inject the contrast dye. The scanner will quickly take pictures as the dye travels into your brain's arteries. You will be asked to remain perfectly still.

The scan itself takes only a few minutes. Because it is often used in emergencies, the process is incredibly streamlined.

Contrast dye is what makes this test an "angiography." The dye highlights the blood flowing through the vessels, allowing the radiologist to see exactly where an aneurysm or blockage is located.

Most people tolerate iodinated contrast well. Allergic-like reactions can occur and severe reactions are rare. Kidney-function testing is based on risk factors and local policy; people with acute kidney injury or severe chronic kidney disease require individual review. Report injection-site pain or swelling, hives, breathing difficulty, or faintness immediately.

If the scan was done for an emergency, the radiologist and your doctor will review the images immediately to make rapid treatment decisions. Otherwise, you can go home and resume normal activities.

CTA uses ionising radiation and iodinated contrast. When it is clinically justified—particularly for suspected stroke, aneurysm, or other vascular emergencies—the expected diagnostic benefit generally outweighs the small radiation and contrast risks. The protocol should still be tailored to the question and patient.

Tell the clinician and CT team if you are pregnant or could be pregnant. Because the pelvis is outside the head beam, fetal radiation exposure is expected to be very low, although iodinated contrast crosses the placenta. A necessary stroke or vascular-emergency CTA should not be delayed when it is the most appropriate timely test.

• RadiologyInfo: CT angiography
• ACR Manual on Contrast Media
• FDA: Computed tomography benefits and risks

A CT Brain Angiography is a rapid and highly effective way to assess the blood vessels in your brain. It delivers the precise information doctors need to treat strokes, aneurysms, and other critical neurological conditions.