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 radiofrequency 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. J. Magn. Reson. Imaging 2011;33:426–431. © 2011 Wiley‐Liss, Inc.