Safety and image quality at 7T MRI for deep brain stimulation systems: Ex vivo study with lead-only and full-systems

Bhumi Bhusal, Jason Stockmann, Bastien Guerin, Azma Mareyam, John Kirsch, Lawrence L. Wald, Mark J. Nolt, Joshua Rosenow, Roberto Lopez-Rosado, Behzad Elahi, Laleh Golestanirad*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Ultra-high field MRI at 7 T can produce much better visualization of sub-cortical structures compared to lower field, which can greatly help target verification as well as overall treatment monitoring for patients with deep brain stimulation (DBS) implants. However, use of 7 T MRI for such patients is currently contra-indicated by guidelines from the device manufacturers due to the safety issues. The aim of this study was to provide an assessment of safety and image quality of ultra-high field magnetic resonance imaging at 7 T in patients with deep brain stimulation implants. We performed experiments with both lead-only and complete DBS systems implanted in anthropomorphic phantoms. RF heating was measured for 43 unique patient-derived device configurations. Magnetic force measurements were performed according to ASTM F2052 test method, and device integrity was assessed before and after experiments. Finally, we assessed electrode artifact in a cadaveric brain implanted with an isolated DBS lead. RF heating remained below 2°C, similar to a fever, with the 95% confidence interval between 0.38°C-0.52°C. Magnetic forces were well below forces imposed by gravity, and thus not a source of concern. No device malfunctioning was observed due to interference from MRI fields. Electrode artifact was most noticeable on MPRAGE and T2∗GRE sequences, while it was minimized on T2-TSE images. Our work provides the safety assessment of ultra-high field MRI at 7 T in patients with DBS implants. Our results suggest that 7 T MRI may be performed safely in patients with DBS implants for specific implant models and MRI hardware.

Original languageEnglish (US)
Article numbere0257077
JournalPloS one
Volume16
Issue number9 September
DOIs
StatePublished - Sep 2021

ASJC Scopus subject areas

  • General

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