The present invention concerns a medical device which can be detected by means of magnetic resonance imaging (MRI). The medical device is characterized by having mechanically stably attached a coating comprising paramagnetic ions which are directly and strongly encompassed by the coating polymers. The medical device comprises a modified envelope polymer providing chemically active free functional groups and a coating covalently bonded to the free functional groups of the envelope polymer at its surface. The coating contains statistically encompassed paramagnetic ions to render it MR visible.
