Resistance and Inductance Based MRI-Safe Implantable Lead Strategies

Paul A. Bottomley¹, William A. Edelstein¹, Ananda Kumar¹, Justin M. Allen¹, Parag Karmarkar¹

Concerns about RF heating of implanted devices routinely denies many patients the benefits of MRI. Here, RF resistive and inductance-based strategies for MRI-safe implanted lead design at 1.5T and 4 W/kg exposure are investigated both experimentally and theoretically using numerical electromagnetic analysis. Phantom studies show that, while unprotected leads heat >45C in seconds, leads fabricated with distributed resistance or coiled, can limit heating as impedance is increased, but lead testing in multiple orientations is important. Such approaches may offer a viable path to MRI-safe implanted lead design, in applications where lead impedance and size do not impair lead utility.