X-ray image of a rat, intravesical implant (2 × 2) mm, Elastollan + barium sulphate + a-C:H/Cu-mulitilayer coating. The selected concentration of 25% barium sulphate in the base material shows sufficient X-ray contrast. X-ray C-arm, Ziehm Vista, Zoom 2, 11 cm, Ziehm Imaging GmbH, Berlin, Germany.