Standard treatment of persons with narrowings of the heart's coronary artery is balloon treatment with implantation of stents (Percutaneous coronary intervention (PCI )). To evaluate disease in coronary arteries prior to, and during PCI , X-ray fluoroscopy with contrast is used. X-ray fluoroscopy produces little information of any disease changes in the vessel wall and implanted stents and especially polylactid acid (PLA) type bioresorbable scaffolds are visualized poorly .