CT Angiography (CTA)

What is CT Angiography?

CT (Computed Tomography) angiography (CTA) is an examination that uses x-rays to visualize blood flow in arterial vessels throughout the body, from arteries serving the brain to those bringing blood to the lungs, kidneys, arms and legs. CT combines the uses of x-rays with computerized analysis of the images. Beams of x-rays are passed from a rotating device throughout the area of interest in the body from several different angles in order to create cross-sectional images. These images are assembled by computer into a three-dimensional picture of the area being studied. CTA is much less invasive and more patient friendly than catheter angiography.

CTA is frequently used to screen for arterial disease. It is commonly used to:

  • Examine the pulmonary arteries in the lungs to rule out pulmonary embolism.

  • Visualize blood flow in the renal arteries in patients with high blood pressure and those suspected of having a kidney disorder.

  • Identify aneurysms in the aorta or in other major blood vessels.

  • Identify dissection(peeling away of the layers of the artery) in the aorta or its major branches.

  • Identify a small neurysm or arterio-venous malfunction inside the brain that can be life-threatening.

  • Detect narrowing or obstruction of arteries in the pelvis and in the carotid arteries bringing blood from the heart to the brain.

  • To help surgeons assess details of the arteries prior to tumor surgery.



Depending on the part of the body to be studied, you may be asked to take only clear liquids by mouth before the CTA. Approximately 20 minutes to one hour should be allowed for the examination. You may be at The Radiology Clinic longer than that due to check-in and interview with the technologist.

If you have children, please make arrangements for childcare, as there are no childcare facilities on site.

What to Expect

CTA takes about 10 to 25 minutes from the time the actual examination begins. Overall, you can expect to be in or near the examining room for 20 to 60 minutes. You may feel warm all over when the contrast material is injected before the scan, but you should not feel pain at any time.

The CT machine resembles a large standing donut, called the gantry, with a table positioned through its center. The gantry houses the rotating x-ray tube and detectors. You will be instructed to lie as still as possible on the examination table. During the exam you will be asked to take remove your glasses, hearing aids or any removable dental work.

You will be moved slowly into the gantry. You will see the CT rotating around you and hear the CT machine make a whirring sound, while the tube moves around your body. There is no discomfort associated wit the CT scan itself.

The technologist will not be in the examination room with you, but he or she will be able to see, hear, and speak to you at all times using an intercom. 

Follow Up

You can eat immediately following the scan. It is very important to increase the amount of water you drink for several days after the exam.

Your referring physician will be provided results 2 - 3 working days after the procedure.

If you are pregnant or feel you may be pregnant, please notifiy the technologist prior to your exam.

The Radiology Clinic is accredited by the American College of Radiology.