An x-ray image of the blood vessels taken after a special dye is injected into the bloodstream. Angiograms can be used to look at arteries such as the lungs (pulmonary angiogram), brain (cerebral angiogram), and heart (coronary angiogram).
To perform an angiogram, a physician first inserts a thin, flexible tube called a catheter into a large artery, most commonly in the arm or the groin area. Then he threads the catheter through the artery until it reaches the desired segment of the blood vessel. Contrast dye is injected via the catheter, and x-ray pictures are taken. This procedure can take up to two or three hours.
Angiograms can be used to diagnose and evaluate a variety of medical conditions, including peripheral vascular disease (blood vessel disease outside the heart and brain), aneurysms (ballooning areas in blood vessels), problems with the blood vessels of the kidneys, and malformed blood vessels.
Angiography may not be suitable for people with diabetic nephropathy because the radiopaque contrast dye may further damage the kidneys. In addition, because of the risk of kidney complications, people who take certain medicines, including metformin (brand names Glucophage, Glucophage XR, Fortamet, and Riomet), may be advised to stop taking them briefly before and after they undergo angiography.