Interventional radiologists pioneered angioplasty and stenting, which was first performed to treat peripheral arterial disease. Using imaging for guidance, an AVIC specialist threads a catheter through the femoral artery in the groin to the blocked artery in the legs. Then he inflates a balloon to open the blood vessel where it is narrowed or blocked. In some cases this is then held open with a stent, a tiny metal cylinder. This is a minimally invasive treatment that does not require surgery, just a nick in the skin the size of a pencil tip.