an endoprosthesis , a method for imaging an endoprosthesis , a method of making an endoprosthesis involve a polymeric substrate that has been modified to have voids embedded within the substrate . the voids are sized to scatter optical radiation from within the substrate so that an optical coherence tomography image can be obtained in which an interior region of the substrate can be easily differentiated from empty space and other structures that surround the endoprosthesis . the voids allow for oct visualization of the polymeric substrate which may be difficult to visualize by other methods such as fluoroscopy .