Modifying surgical implantation of deep brain stimulation leads significantly reduces RF-induced heating during 3 T MRI.

Abstract

Radiofrequency (RF) heating of tissue during magnetic resonance imaging (MRI) is a known safety risk in the presence of active implantable medical devices (AIMDs). As a result, access to MRI is limited for patients with these implants including those with deep brain stimulation (DBS) systems. Numerous factors contribute to excessive RF tissue heating at the DBS lead-tip, most notable being the trajectory of the lead. Phantom studies have demonstrated that looping the extracranial portion of the DBS lead at the surgical burr hole reduces the heating at the lead-tip; however, clinical implementation of this technique is challenging due to surgical constraints. As such, the intended looped trajectory is usually different from what is implanted in patients. To date, no data is available to quantify the extent by which surgical trajectory modification reduces RF heating of DBS leads compared to the typical surgical approach. In this work, we measured RF heating of a commercial DBS system during 3 T MRI, where the trajectory of the lead and extension cable mimicked lead trajectories constructed from postoperative CT images of 13 patients undergoing modified DBS surgery and 2 patients with unmodified trajectories. Two manually created trajectories mimicking typical heating cases seen in the literature were also evaluated. We found that modified lead trajectories reduced the average heating by 3-folds compared to unmodified lead trajectories.Clinical Relevance- This study evaluates the performance of a surgical modification in the routing of DBS leads in reducing RF-induced heating during MRI at 3 T.