The presence of an abandoned lead during MRI exposure modified the RF-heating profile of an MR-conditional pacemaker, causing temperature variations ranging from -63% to +69% at the lead tip.
Does the presence of an abandoned lead increase the risk of RF-induced heating in patients with MR-conditional pacemaker systems during MRI?
The presence of an abandoned lead poses an additional risk of RF-induced heating for patients with MR-conditional pacemakers, supporting current manufacturer policies against MRI in these patients.
PURPOSE: To assess the risk of radiofrequency (RF)-induced heating in patients with MR-conditional pacemaker (PM) systems, in the presence of another lead abandoned from a previous implant. METHODS: Four commercial pacemaker leads were placed beside a MR-conditional PM system, inside a human trunk simulator. The phantom has been exposed to the RF generated by a 64 MHz body bird-cage coil (whole-body specific absorption rate SAR = 1 W/kg) and the induced heating was measured at the tip of the abandoned lead and of the MR-conditional implant. Configurations that maximize the coupling between the RF field and the leads have been tested, as well as realistic implant positions. RESULTS: Abandoned leads showed heating behaviors that strongly depend on the termination condition (abandoned-capped or saline exposed) and on the lead path (left or right positioning). Given a whole-body SAR = 1 W/kg, a maximum temperature rise of 17.6°C was observed. The presence of the abandoned lead modifies the RF-heating profile of the MR-conditional implant: either an increase or a decrease in the induced heating at its lead tip can occur, mainly depending on the relative position of the two leads. Variations ranging from -63% to +69% with respect to the MR-conditional system alone were observed. CONCLUSION: These findings provide experimental evidence that the presence of an abandoned lead poses an additional risk for the patient implanted with a MR-conditional PM system. Our results support the current PM manufacturers' policy of conditioning the MR compatibility of their systems to the absence of abandoned leads (including leads from MR-conditional implants). From a clinical point of view, in such cases, the decision whether to perform the exam shall be based upon a risk/benefit evaluation, as in the case of conventional PM systems.
Mattei et al. (Thu,) conducted a other in MR-conditional pacemaker systems with abandoned leads. Presence of capped or uncapped abandoned leads during MRI RF exposure vs. MR-conditional system alone was evaluated on Radiofrequency-induced heating at the tip of the abandoned lead and MR-conditional implant. The presence of an abandoned lead during MRI exposure modified the RF-heating profile of an MR-conditional pacemaker, causing temperature variations ranging from -63% to +69% at the lead tip.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: