Mikhail Kozlov and Gregor Schaefers
Computational electromagnetics, simulation, implants, MR safety
For insulated stainless steel wires of 1.5 mm in diameter with 0.5 mm insulation thickness, we evaluated the dependence of 64 MHz RF-induced power deposited at a hotspot (p) on: 1) lead length, 2) lead insulating electrical properties, 3) lead surrounding medium. Lead transfer functions (TF) were obtained with 3-D electromagnetic simulations. TF and p depended significantly on electrical properties of the insulation and lead surrounding medium. Increased insulator conductivity resulted in decreased p in most investigated cases. It is impossible to define one test surrounding medium that results in worst case power deposition for all cases: a) different lead lengths; b) different electrical properties of the lead insulator; and c) different tissues surrounding the lead in human body.