How does an angiogram work?

A typical x-ray works by casting a "shadow" on film when it is exposed to the x-ray, much like when you hold a flashlight up to your hand and cast a shadow on a wall. Normally your blood vessels cannot be seen in an x-ray, but adding a contrast agent into the blood stream through a catheter makes your blood vessels show up on the film, sort of like a roadmap .

A machine called a fluoroscope, also called a C-arm, is an arc shaped piece of equipment that generates x-rays from one side and photographs them on the other side.

Today many catheter angiographic studies have been replaced by less invasive methods such as computed tomography angiography (CTA) and magnetic resonance angiography (MRA) that do not require a catheter be inserted. Catheter angiography has the benefit of combining diagnosis and treatment in patients who may undergo surgery or other endovascular procedure such as angioplasty, coiling, balloon, or stent placement.

What does an angiogram show?

Angiograms are very good at detecting problems with the blood vessels such as an aneurysm, arteriovenous malformation (AVM), arterial stenosis (narrowing of the arteries due to atherosclerosis), tumor, and clots.

How does the contrast agent work?

The contrast agent contains iodine, a substance that x-rays cannot pass through. The contrast circulates through your blood stream and can be x-rayed as it passes through the neck, brain or spinal column.