A diagnostic angiogram is used to examine the inside of arteries and veins to detect blockages or narrowing of the vessels. In angioplasty, a catheter fitted with a balloon device is guided to the affected area to expand the walls and restore blood flow, or a laser can be used to break up the blockage. In some cases, a stent (mesh tube) is placed in the artery to hold it open. Angioplasty can be used to treat everything from heart disease and circulatory problems to ischemic stroke.