The present invention concerns a medical device detectable by magnetic resonance imaging (MRI), said medical device comprising an envelope polymer that is at least partly removed at the distal end of the medical device wherein said distal end is provided with a coating comprising a coating polymer modified with at least one chemical compound having one or more chemically active free functional groups to provide a surface coating covalently bonded to the free functional groups of the modified coating polymer, wherein paramagnetic ions are encompassed in the coating.