CT angiography involves the injection of contrast dye into a large blood vessel, to help visualize the blood vessels and the blood flow within them.

CT angiography is similar to a CT scan, but the contrast dye is injected into one of your veins shortly before the x ray image is performed.

Because the dye is injected into a vein rather than into an artery, as in traditional angiography, CT angiography could be considered less invasive.