Computed Tomography Angiography (CTA)

What is computed tomography angiography?

Computed tomography angiography, also known as a CTA or CT angiography, is a diagnostic imaging technique that uses a computed tomography (CT) scanner. A CT scanner is a combination of a specialized X-ray scanner and sophisticated computer analysis.

CT angiography provides detailed, three-dimensional images of the blood vessels, such as those in the brain. A special dye, known as contrast, is injected during the test to provide a clearer picture of the blood vessels and certain structures inside the head.

The test helps physicians identify weakened sections of arteries or veins, and better visualize blood flow. This can help medical teams identify the cause and location of a stroke, as well as observe any associated damage to the brain.

What happens during a CT angiography scan?

For a CT angiogram, the patient wears a hospital gown and lies flat on an examination table. A nurse or technician will insert an IV, which is used to inject the contrast into the bloodstream.

The examination table slides into the machine. A technician will talk to the patient through speakers and may ask them to hold their breath for 10 to 25 seconds at a time, so clearer pictures may be taken.

How long will the test take?

The actual test is brief, approximately 15 to 30 minutes. However, if it is being done on a patient who is not currently admitted to the hospital (outpatient), the time from check-in to finish is about an hour and a half.

Does the test cause any discomfort?

While the actual scans are painless, some patients may experience a pinch during insertion of the IV. Patients also report a warm sensation throughout the body and a metallic taste in the mouth after the contrast is injected. This is normal.

What preparations are needed before CT angiography?

If the patient is an outpatient, they will be asked not to eat anything solid for at least four hours prior to the test. Upon arrival, a radiology nurse or technologist will ask a few questions about the patient’s medical history. Also, patients are encouraged to wear easy-to-remove clothing, because they will be required to change into a hospital gown for the procedure. Valuables should be left at home.

Anyone undergoing CT angiography, inpatient or outpatient, should tell their medical team if they are or might be pregnant and alert them to any allergies.

What happens when the test is done?

After the test, patients may resume their normal diet, and should drink plenty of fluids to help flush the contrast from their body.

An imaging physician will examine the images and send a written report to the patient’s physician, who will contact the patient with the results.

For an appointment, a second opinion or more information, please call 1-800-CEDARS-1 (1-800-233-2771) or email us at neurologicaldisorders@cshs.org.