RF Safety Assessment of a Generic Deep Brain Stimulator During 1.5T MRI Exposure

Eugenia Cabot¹, Tom Lloyd², Andreas Christ¹, Gregg Stenzel², Wolfgang Kainz³, Steve Wedan², Niels Kuster^1,4

A methodology for RF safety assessment of implants based on a 4 tier approach was evaluated for 1.5T scanners using a generic model of a deep brain stimulator. A combination of numerical (FDTD simulations) and experimental techniques was used. The different tiers were followed to assess the energy deposition and the temperature increase at the tip of the implant in a human head model. Each consecutive tier yields a less conservative result, but requires greater computational effort to demonstrate safety. Results showed that Tier 4 is technically feasible but too computationally demanding. An enhanced Tier 3 is then suggested.