Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, California, USA.
J Magn Reson Imaging. 2011 Feb;33(2):426-31. doi: 10.1002/jmri.22463.
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.
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.
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.
Current recommendations for MRI pacemaker safety should highlight the possible increased risk for patients with abandoned leads as compared to pacemaker-attached leads.
通过在 1.5T 下测量体外温度，评估与起搏器相连和废弃的导联中射频诱导加热的风险，作为导联长度的函数。
将五个定制长度（20-60cm）的导联暴露于均匀幅度和相位射频电场中，以研究导联长度对起搏器相连和废弃的起搏器导联的起搏器导联尖端加热的影响。
废弃和与起搏器相连的导联表现出共振加热行为，由于终止条件的不同，最大加热发生在不同的导联长度处。对于临床导联长度（40-60cm），与与起搏器相连的导联相比，废弃导联表现出更大的导联尖端加热。
与与起搏器相连的导联相比，目前关于 MRI 起搏器安全性的建议应强调患者使用废弃导联可能存在的风险增加。
