Balloon angioplasty in coronary artery disease - post-treatment image. False-colour coronary angiogram showing the successful result of balloon angioplasty, with the restoration of a narrowed section of the circumflex artery. The treated section is to the upper left of the point where two major arteries (red) appear to cross over. Balloon angioplasty aims to restore the patency of selected atherosclerotic arteries. To do so, a catheter carrying a cigar-shaped, inflatable balloon is guided by X-ray imaging into the affected artery. Once in position, the balloon is carefully inflated to compress the atheroma deposit & so restore normal blood flow. M172/175 & M172/176 show images pre- and during treatment; with this image they comprise a series of 3.