Pacemaker Lead Tip Heating in Abandoned and Pacemaker-Attached Leads at 1.5 Tesla MRI

Purpose: To assess the risk of RF-induced heating in pacemaker-attached and abandoned leads using in vitro temperature measurements at 1.5 Tesla as a function of lead length. Materials and Methods: Five custom lead lengths, 20-60 cm, were exposed to a uniform magnitude and phase radio-frequency electric field to examine the effect of lead length on pacemaker lead tip heating for pacemaker-attached and abandoned pacemaker leads. Results: Abandoned and pacemaker-attached leads show resonant heating behavior and maximum heating occurs at different lead lengths due to the differences in termination conditions. For clinical lead lengths (40-60 cm) abandoned leads exhibited greater lead tip heating compared with pacemaker-attached leads. Conclusion: Current recommendations for MRI pacemaker safety should highlight the possible increased risk for patients with abandoned leads as compared to pacemaker-attached leads.