In vitro measurements on 30 commercial pacemaker and defibrillator leads exposed to a 1.5 T MRI field showed that structural properties reported in device documents are insufficient to estimate heating.
Can structural properties of pacemaker/defibrillator leads predict MRI-induced heating?
Structural properties reported in device documents are insufficient to predict MRI-induced heating of pacemaker and ICD leads.
MRI-induced heating on endocardial leads is a serious concern for the safety of patients with implantable pacemakers or cardioverter-defibrillator. The lead heating depends on many factors and its amount is largely variable. In this study, we investigated the role of those structural properties of the lead that are reported on the accompanying documents of the device: (1) fixation modality (active vs. passive); (2) number of electrodes (unipolar vs. bipolar); (3) length; (4) tip surface; and (5) tip and ring resistance. In vitro temperature and specific absorption rate measurements on 30 leads (27 pacemakers, three implantable cardioverter-defibrillator leads) exposed to the radiofrequency field typical of a 1.5 T MRI scanner are presented. The data show that each lead has its own attitude to radiofrequency-induced heating and that the information that is available in the accompanying documents of the pacemaker is not sufficient to explain such attitude. Even if combined with that of the implant geometry, this information is still not sufficient to estimate the amount of heating due to the exposure to the radiofrequency field during MRI examination.
Mattei et al. (Mon,) conducted a other in MRI-induced heating on endocardial leads (n=30). Exposure to 1.5 T MRI radiofrequency field was evaluated on In vitro temperature and specific absorption rate measurements. In vitro measurements on 30 commercial pacemaker and defibrillator leads exposed to a 1.5 T MRI field showed that structural properties reported in device documents are insufficient to estimate heating.