A monolithically fabricated flexible resonant circuit for catheter tracking in magnetic resonance imaging

To track a flexible catheter with a magnetic resonance imaging (MRI) scanner a wireless resonant circuit has been monolithically integrated into a less than 50 μm thin foil of polyimide. This biocompatible device, protected by a coating of parylene-C, can be attached to catheters with a diameter of at least 5 French. Detailed simulations and measurements have been performed to insure a perfect operation on the instrument for different surrounding liquids. First MRI images in a 1.5 T tomograph show clearly tracking spots with a diameter of about 2.5 mm.