Steffen Weiss1, Bernd David1,
Oliver Lips1, Jan Hendrik Wuelbern1, Sascha Krueger1
1Philips Research
Laboratories,
Various methods have been used to limit MR-induced RF currents and associated RF heating in wired interventional devices, including resistors, resonant RF chokes, transformers, and mechanical switches as current-limiting elements. Here, RF heating for six such transmission lines was evaluated at the tip and along the full length of the line using fiber-optic probes and an infrared camera simultaneously. While all methods effectively suppressed tip heating, heating at the current limiting elements was largest for resonant chokes and lowest for transformers and switches. The IR imaging method is suitable to quickly and globally identify sources of ohmic heating.
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