Computed Tomography Angiography (CTA)

Overview

A CT angiogram (CTA) is a special type of CT scan that creates very detailed pictures of the aorta and its branches. It uses X-rays taken from many angles and a contrast dye to clearly show blood vessels. During the test, you lie on a table that moves through the CT scanner while the dye, usually injected into a vein in your arm, helps the aorta and surrounding vessels stand out.

CTA produces cross-sectional images that can be combined into 3D views. It is one of the most accurate and commonly used tests to find problems such as aortic aneurysms, dissections (tears), blockages, or other abnormalities. Because it is quick and widely available, it is often used in emergencies.

How It Works

A small amount of contrast dye is injected into a vein to make the blood vessels visible on the scan. As you move through the CT scanner, X-rays are taken rapidly from many directions. A computer then combines these images to create detailed pictures of your aorta, which can also be viewed in 3D. The whole test usually takes only a few minutes.

When It’s Used

Doctors recommend a CT angiogram to:

  • Detect or confirm an aortic dissection or rupture in emergencies.

  • Measure and monitor the size of an aneurysm.

  • Look for blockages, ulcers, or other abnormalities in the blood vessels.

  • Plan surgery or endovascular procedures involving the aorta.

Because it is fast and highly detailed, CTA is often the first imaging test used when serious aortic disease is suspected.

What It May Not Find

Although CTA is very accurate, there are still some limits:

  • Very early inflammation or minor infections in the aortic wall may not be visible.

  • Small branches of the blood vessels can be difficult to assess clearly.

  • The scan shows structure extremely well but does not show how tissues function or their metabolic activity. For this, MRI or PET scans may be recommended.

Complications

A CT angiogram is generally safe, but a few risks exist:

  • Radiation exposure: CTA uses more radiation than a standard X-ray, though the benefit usually outweighs the risk.

  • Allergic reaction: Some people may react to the contrast dye, but this is uncommon.

  • Kidney strain: The contrast may temporarily affect kidney function, especially in those with kidney disease.

Your medical team will review your health and medical history to decide if CTA is the most appropriate test for you.

How It Is Useful in Aortic Disease

CT angiography is particularly helpful for:

  • Detecting and measuring aortic aneurysms.

  • Confirming or ruling out aortic dissection.

  • Mapping the aorta and nearby vessels for surgical or stent procedures.

  • Following up after surgery or endovascular repair to check healing or detect complications.

Because CTA provides clear, detailed images quickly, it is one of the most important tools for diagnosing and managing aortic disease, especially in urgent situations.