Additive RF and Gradient-induced Heating of Passive and Active Implants Under Clinically Relevant Exposures during MRI

Motivation: RF- and gradient-induced heating of implants during MRI are estimated independently, and it is often assumed that under clinically relevant conditions they are not significantly additive. Goal(s): To investigate realistic MR conditions under which the RF- and gradient-induced heating can be additive. Approach: Virtual Population phantoms with hip, knee, shoulder, ankle, and cranial implants, and an active implant IPG, were assessed with EPI, FISP, and TSE sequences for RF and gradient-induced heating. Results: Maximum local temperature rise increased up to 15% when both RF and gradient heating were considered in hip, knee and shoulder implants during EPI scans. Impact: Bulky nonmagnetic metallic implants are demonstrated to experience up to 15 % increase in maximum local temperature rise due to additive RF and gradient-induced heating under clinically relevant MRI exposure conditions.