Angiogram is an x-ray of the arteries. It is performed by puncturing the artery under local anesthetic, and injecting contrast (dye) to outline the blood vessels. A reduction in the blood supply to the kidneys can give rise to poor renal function and high blood pressure. The kidney arteries can become narrowed by atheroma (hardening of the arteries). In this case, the narrowed artery can be stretched with a balloon angioplasty and stenting to improve blood flow, this will help to reduce blood pressure and maintain better kidney function.