Deep brain stimulation lead-contact heating during 3T MRI: single- versus dual-channel pulse generator configurations

Abstract

Background: Magnetic resonance imaging (MRI) after deep brain stimulation (DBS) carries the risk of heating at the lead-contacts within the brain. Objective/Hypothesis: To compare the effect of single- and dual-channel DBS implantable pulse generator (IPG) configurations on brain lead-contact heating during 3T MRI. Methods: A phantom with bilateral brain leads and extensions connected to two single-channel IPGs or a dual-channel right or left IPG was utilized. Using a transmit/receive head coil, seven scan sequences were conducted yielding a range of head-specific absorption rates (SAR-H). Temperature changes (ΔT) at the bilateral 0 and 3 lead-contacts were recorded, and normalized temperatures (ΔT/SAR-H) and slopes defining the ΔT/SAR-H over the SAR-H range were compared. Results: Greater heating was strongly correlated with higher SAR-H in all configurations. For each scan sequence, the ΔT/SAR-H of single-channel left lead-contacts was significantly greater than the ΔT/SAR-H of either dual-channel configuration. The slope defining the relationship between ΔT and SAR-H for the single-channel left lead (1.68°C/SAR-H) was significantly greater (p < 0.0001) than the ΔT/SAR-H slope for the single-channel right lead (0.97°C/SAR-H), both of which were significantly greater (p < 0.0001) than the ΔT/SAR-H slopes of left or right leads (range 0.68 to 0.70°C/SAR-H) in the dual-channel configurations. There were no significant differences in ΔT/SAR-H slope values between the dual-channel configurations. Conclusion: DBS hardware configuration using bilateral single-channel versus unilateral dual-channel IPGs significantly affects DBS lead-contact heating during 3T MRI brain scanning.

KEYWORDS: :

• deep brain stimulation
• magnetic resonance imaging
• 3T
• specific absorption rate

Acknowledgements

The authors acknowledge Sang-Pil Lee of the Hoglund Brain Imaging Center, KUMC for helpful insights regarding MRI physics, and Allen Schmitt RT (R) (MR) and Lisa Nelson, RT (R) (MR) (CT) (N), Hoglund Brain Imaging Center, KUMC for operation of the MRI machine and assistance within the scanner throughout these experiments.