Angiography is a test that uses dye and special x rays to show the inside of your arteries. This test can show whether plaque is blocking your arteries and how severe the blockage is.
A thin, flexible tube called a catheter is put into a blood vessel in your arm, groin (upper thigh), or neck. Dye that can be seen on an x-ray picture is injected through the catheter into the arteries. By looking at the x-ray picture, your doctor can see the flow of blood through your arteries.