MRI Heating Reduction for External Fixation Devices Using Absorption Material

This paper presents a novel approach to minimize the radio frequency (RF)-induced heating from external fixation devices under magnetic resonance imaging (MRI) procedure. With proper placement and selection of absorption material, one can alter the electromagnetic field and current distributions around and/or on medical devices so that the MRI RF field-induced heating can be reduced. The absorption-material-based RF heating reduction schemes are analyzed and validated. Numerical and experimental studies are conducted to illustrate the potentials of reducing the RF heating for external fixation devices. A design strategy based on response surface methodology is presented for material selection, and it is shown that absorption materials can significantly reduce the RF heating effects from 645 to 172 W/kg in terms of 1-g spatial-averaged SAR for the device under this investigation.