A lead includes a conductor having a distal end and a proximal end and a resonant circuit connected to the conductor. The resonant circuit has a resonance frequency approximately equal to an excitation signal's frequency of a magnetic resonance imaging scanner or a resonance frequency not tuned to an excitation signal's frequency of a magnetic resonance imaging scanner so as to reduce the current flow through a tissue area, thereby reducing tissue damage. The resonant circuit may be included in an adapter that provides an electrical bridge between a lead a medical device such as an electrode, sensor, or signal generator. The resonant circuit may also be included directly in the housing of a medical device.