Laleh Golestani Rad1
1Northwestern University, Chicago, IL, United States
Synopsis
MRI is useful in patients with DBS devices for electrode localization and monitoring functional effects of the stimulation. This talk gives an overview of safety issues and technical challenges of MRI in patients with DBS implants. Major risks of off label use of MRI are discussed in the light of recent studies that highlight the effect of lead trajectory and patient’s body composition on RF heating of DBS leads and recommendations are provided to mitigate the risks through surgical lead management.
Introduction
75% of patients with deep brain stimulation devices will need MRI through their lifetime. MRI is not easily accessible to these patients due to risks associated with interaction of MRI fields with active electronic implants. This talk provides an overview of technical challenges and safety issues regarding MRI of patients with deep brain stimulation (DBS) implants. We start by giving an overview of DBS system components and describe sources of MRI hazard due to their interaction with RF, gradient, and static magnetic fields. We then go over examples of MR-Conditional labeling of DBS devices, review critical information, and discuss common misconceptions. Although discouraged, off label use of MRI happens in patients with DBS devices. RF heating of the tissue at the tip of DBS lead is the major safety risk when patients are scanned at unapproved fields or with pulse sequences with higher than recommended SAR or B1 levels. We discuss ramification of such practices in the light of recent studies that have highlighted the effect of DBS device configuration and patient’s body composition on the RF heating (1,2). Finally, we discuss mitigation strategies to reduce risk of MRI by modifying surgical implantation of DBS leads (3). Syllabuys
- Overview of DBS system components and sources of MRI hazard
- MR-Conditional devices: What to look for in the labeling, Common misconceptions
- Off label use of MRI in patients with DBS implants: Major risks, Dos and Don'ts
- Mitigation strategies: How to reduce RF heating through surgical modification of lead trajectory
Acknowledgements
No acknowledgement found.References
1. Bhusal B, Nguyen BT, Sanpitak PP, Vu J, Elahi B, Rosenow J, Nolt MJ, Lopez‐Rosado R, Pilitsis J, DiMarzio M. Effect of Device Configuration and Patient's Body Composition on the RF Heating and Nonsusceptibility Artifact of Deep Brain Stimulation Implants During MRI at 1.5 T and 3T. Journal of Magnetic Resonance Imaging 2020;53(2):599-610.2.
2. Bhusal B, Keil B, Rosenow J, Kazemivalipour E, Golestanirad L. Patient’s body composition can significantly affect RF power deposition in the tissue around DBS implants: ramifications for lead management strategies and MRI field-shaping techniques. Physics in Medicine & Biology 2021;66(1):015008.3.
3. Golestanirad L, Kirsch J, Bonmassar G, Downs S, Elahi B, Martin A, Iacono M-I, Angelone LM, Keil B, Wald LL. RF-induced heating in tissue near bilateral DBS implants during MRI at 1.5 T and 3T: The role of surgical lead management. NeuroImage 2019;184:566-576