Computed Tomography Angiogram (CT Angiogram)
What Affects the Test
You may not be able to have a CT angiogram if:
- You are pregnant. A CT angiogram isn't usually done when a woman is pregnant, because there is a chance that the baby might be harmed by the radiation.
- You have had an X-ray test that used barium contrast material (such as a barium enema) in the past 4 days. Barium shows up on a CT angiogram and makes it hard to see the picture clearly. A CT angiogram should be done before any tests that use barium.
- You are allergic to the dye (contrast material) that is used during the test.
- You have kidney problems. The dye used during the test can cause kidney damage in people whose kidneys don't work well.
- You take metformin (such as Glucophage) to control your diabetes. The dye used during the test may cause problems if you take this medicine.
- You are obese. A person who is very overweight may not fit into a standard CT machine, or the X-ray table may not be able to support his or her weight.
- You can't lie still during the test.
- You have metal objects in your body, such as surgical clips or metal in joint replacements. These objects may prevent a clear view of the areas being examined.
What To Think About
Benefits and limitations
A CT angiogram is a less invasive test than a standard angiogram. A standard angiogram involves threading a thin tube called a catheter through an artery in your arm or leg up to the area being studied. But with a CT angiogram, no tubes are put in your body. To learn more, see the topic Angiogram.
If your doctor sees that one or more of your blood vessels are narrowed or blocked, you may need a standard angiogram anyway to double-check the abnormal results from the CT angiogram. This is more likely to happen if your doctor is considering surgery to treat the narrowing or blockage.
If your doctor finds a major blockage in one of your blood vessels during a CT angiogram, you won't be able to get an immediate angioplasty to clear the blockage. You will need a separate procedure. But if you have a standard angiogram and the doctor finds a major blockage, he or she can perform an angioplasty during the angiogram.