The presence of a second wire-like conducting implant during 3T MRI can increase RF-induced heating near the tip of the conductor by as much as 95% due to electromagnetic coupling.
Does the presence of multiple wire-like conducting implants increase RF-induced heating during 3T MRI?
RF coupling between multiple wire-like implants during MRI can significantly increase local heating, highlighting an important safety consideration.
Effect estimate: Up to 95% increase
PURPOSE: In this study, the effects of RF coupling on the magnitude and spatial patterns of RF-induced heating near multiple wire-like conducting implants (such as simultaneous electrical stimulation of stereoelectroencephalography electrodes) during MRI were assessed. METHODS: Simulations and experimental measurements of RF-induced temperature increases near partially immersed wire-like conductors were performed using a phantom with a transmit/receive head coil on a 3T MRI system. The conductors consisted of either a pair of wires or a single simultaneous electrical stimulation of stereoelectroencephalography electrode with multiple contacts, and the locations and lengths of the conductors were varied to study the effect of electromagnetic coupling on RF-induced heating. RESULTS: The temperature increase near a wire within the phantom was dependent not only on its own location and length, but also on the locations and lengths of the other partially immersed wires. In the configurations that were studied, the presence of a second implant could increase the heating near the tip of the conductor by as much as 95%. CONCLUSION: The level of RF-induced heating during an MR scan is affected significantly by RF coupling when more than one wire-like implant is present. In some of the configurations studied, the heating was increased by the presence of a second conductor partially immersed in the phantom. Thus, RF coupling is an important factor to consider in the assessment of safety issues for MRI when multiple implants are present.
Bhusal et al. (Fri,) reported a other. Presence of multiple wire-like conducting implants vs. Single wire-like conducting implant was evaluated on RF-induced temperature increase near the conductor tip (Up to 95% increase). The presence of a second wire-like conducting implant during 3T MRI can increase RF-induced heating near the tip of the conductor by as much as 95% due to electromagnetic coupling.