The Importance of Sensor Placement During the Measurement of RF Heating of Implants in MRI

This study investigates the importance of accurate sensor placement when assessing implant safety during MRI scans experimentally. A combination of measurement and finite element modelling was used to assess sensitivity of measurement to sensor placement, for temperature rises at the ends of a set of calibration cylinders. The simulations used a coupled thermal-electromagnetic model created using COMSOL Multiphysics to replicate the measurement conditions virtually. Thermal gradients in parametric models of cylindrical implants of varying length and diameter were evaluated to quantify the sensor placement accuracy required for the measurement of implant heating within the estimated temperature measurement uncertainty. In this way we aim to enhance the understanding of the requirements for experimental procedures and safety standards dealing with implant heating in MRI.