A narrow spot in an artery may
suggest that a blood clot or a deposit of fat and calcium is reducing blood
flow through the blood vessel.
An abnormal pattern of blood
vessels may be a sign that a tumor is present.
What Affects the Test
You may not be able to have a CT
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
contrast material (such as a
barium enema) or have taken a medicine that contains
bismuth (such as Pepto-Bismol) in the past 4 days. These substances show up on
a CT angiogram and make it hard to see the picture clearly. A CT angiogram
should be done before any tests that use these substances.
allergic to the dye (contrast material) that is used during the
You have kidney problems. The dye used during the test can
cause kidney damage in people whose kidneys don't work well.
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.
You have an implanted or
externally worn medical device, such as a pacemaker, a heart defibrillator, a
neurostimulator, or a drug infusion pump. These medical devices may not work
well during a CT scan.
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. For more information, see the medical test