The Freestyle subcoronary bioprosthesis, Models 995CS and 995MS, is magnetic resonance (MR) safe. The bioprosthesis contains no metal and, therefore, poses no known hazards in all MR environments. The device will not cause any harm to the patient when exposed to MR scanning immediately after implantation. MRI at 3.0 T and 1.5 T may be performed immediately following implantation of the device.