An angiogram is an X-ray test that provides pictures of the blood flow in a blood vessel. During an angiogram, a material that shows up on an X-ray (contrast material) is put into a blood vessel through a thin tube (catheter).

An angiogram may be done to look for problems such as a tear in a blood vessel that can cause blockage or bleeding, aneurysms (which are weaknesses in the blood vessel wall), and blood clots or the buildup of fatty deposits.

Sometimes a problem can be treated during angiography. For example, a catheter can be used to open a blocked blood vessel, deliver medicine to a tumor, or stop bleeding in the intestines.