an optical coupling is incorporated into an invasive device used in magnetic resonance imaging . the coupling is incorporated into the invasive device between an imaging or tracking rf coil , and the mr receiver . the optical coupling has a first transducer circuit coupled to the rf which converts between optical and electrical signals . an optical fiber is coupled to the first transducer circuit and extends out of the invasive device to medical imaging equipment . near this equipment , a second transducer circuit converts optical signals to electrical , and electrical signals to optical , just opposite that of the first transducer circuit . the present invention thereby replaces long lead wires which can cause heating during mr imaging , and may distort an mr image .