Computed Tomographic Angiography



A CTA test is relatively low risk, though most reactions to CTA are due to the contrast dye. If you have an iodine allergy, you should mention it to your doctor before receiving intravenous contrast dye.

Reactions may include the following:

  • Most people experience a harmless sensation of warmth that passes quickly.
  • If you have an allergic reaction, you may experience flushing; itching; and, rarely, trouble breathing and swallowing.
  • Redness, swelling, and pain may occur if the dye leaks under your skin where it’s injected.
  • Depending on various factors, the dye can also damage kidney function, though kidney failure is rare. If you have diabetes are on medications for diabetes, or have known kidney problems, be sure to discuss these factors with your doctor before the CTA test.

A CTA carries some radiation risk, as do all X-ray imaging tests. Operational controls and professional standards are in place in hospitals to reduce the risk of radiation exposure beyond very small doses. Typically, the main concern is to reduce lifetime radiation exposure. That is, a CTA should only be ordered when the benefits of gathering the images are clear and can’t be achieved through a method that doesn’t use ionizing radiation.