A. Melzer, K. Horvath, M. Guttman, M. Li, E. Immel, R. Lederman, J. Spilner, C. Lorenz, E. McVeigh Physical Engineering, Radiology, INSITE med. University Gelsenkrichen, Gelsenkirchen, Germany, NHLBI, NIH, Bethesda, MD, United States, Biophan, Castrop Rauxel, Germany, RWTH Aachen, Aachen, Germany, Siemens, Erlangen, Germany Introduction: Current aortic valve prosthesis comprise either glutaraledhyde preserved porcine valves that are sewed to a polyester fabric frame or mechanical valves comprising a metal ring and synthetic valve mechanisms. Percutaenous valve repair [1] makes use of balloon expanding stents with a bovine jugular vein valves for repair of the pulmonary artery [2] or self expanding (CoreValve) and balloon expanding stents with polymer valves [3]. During x-ray guided placement the positioning of the valve in the correct orientation and secure anchoring is difficult to achieve due to the lack of soft tissue contrast. The metal leads to susceptibility artifacts and RF shielding of the valves compromising diagnostic value of MRI. The purpose of this study was to improve visualization of a percutaneously implantable heart valve under MRI trough the use of a resonant circuit [4]. Material and methods: As the bioprosthetic valves show the best long-term clinical results we have selected these valves and a self expanding stent frame for the basic design. A porcine heart valve was dissected and sewed in to 24 mm x 40 mm. Nitinol stent (Memothem, Bard Angiomed Karlsruhe, Germany) with 4-0 Prolene (Ethicon). A resonant circuit was designed comprising a meandered helical coil as inductive component (8,18 μH) and a non-magnetic 30pF SMD (Surface Mounted Device) as capacitive component. The resonator was tuned to the frequency of 63.8 MHz and the wire insulated with a polyamide tube to provide an appropriate quality factor and to facilitate fixation. It was sewn with a polyfilament 2-0 polyester thread to the stent struts in a wave form to achieve controlled compression and expansion whereby the resonator functions remains. This stent valve was tested in 1.5 T Siemens Sonata and Espree. The MR tests were performed in 1 liter distilled water with 0.9% NaCl at 21° Celsius ambient pressure in a Tupper ware container (113mm x 113mm x 55mm). The container was placed in the standard head coil.