This minimally invasive medical test helps doctors diagnose and treat a variety of medical conditions. Frequently, a contrast dye is injected through an IV during the CT scan to produce detailed images of your blood vessels and tissues. A CT angiogram helps us determine if a blood vessel is blocked. If it is blocked, the images then allow us to find where the blockage is, as well as how big it is. It also helps us identify aneurysms or plaque buildup. CT angiograms are less invasive than standard angiograms.