English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
  Safety Evaluation of a New Setup for Transcranial Electric Stimulation during Magnetic Resonance Imaging

Gregersen, F., Göksu, C., Schaefers, G., Xue, R., Thielscher, A., & Hanson, L. (2021). Safety Evaluation of a New Setup for Transcranial Electric Stimulation during Magnetic Resonance Imaging. Brain Stimulation, 14(3), 488-497. doi:10.1016/j.brs.2021.02.019.

Item is

Basic

show hide
Genre: Journal Article

Files

show Files

Locators

show

Creators

show
hide
 Creators:
Gregersen, F, Author
Göksu, C1, 2, Author              
Schaefers, G, Author
Xue, R, Author
Thielscher, A, Author              
Hanson, LG, Author
Affiliations:
1Department High-Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Max Planck Society, ou_1497796              
2Max Planck Institute for Biological Cybernetics, Max Planck Society, Spemannstrasse 38, 72076 Tübingen, DE, ou_1497794              

Content

show
hide
Free keywords: -
 Abstract: Background: Transcranial electric stimulation during MR imaging can introduce safety issues due to coupling of the RF field with the stimulation electrodes and leads. Objective: To optimize the stimulation setup for MR current density imaging (MRCDI) and increase maximum stimulation current, a new low-conductivity (σ = 29.4 S/m) lead wire is designed and tested. Method: The antenna effect was simulated to investigate the effect of lead conductivity. Subsequently, specific absorption rate (SAR) simulations for realistic lead configurations with low-conductivity leads and two electrode types were performed at 128 MHz and 298 MHz being the Larmor frequencies of protons at 3T and 7T. Temperature measurements were performed during MRI using high power deposition sequences to ensure that the electrodes comply with MRI temperature regulations. Results: The antenna effect was found for copper leads at ¼ RF wavelength and could be reliably eliminated using low-conductivity leads. Realistic lead configurations increased the head SAR and the local head SAR at the electrodes only minimally. The highest temperatures were measured on the rings of center-surround electrodes, while circular electrodes showed little heating. No temperature increase above the safety limit of 39 °C was observed. Conclusion: Coupling to the RF field can be reliably prevented by low-conductivity leads, enabling cable paths optimal for MRCDI. Compared to commercial copper leads with safety resistors, the low-conductivity leads had lower total impedance, enabling the application of higher currents without changing stimulator design. Attention must be paid to electrode pads.

Details

show
hide
Language(s):
 Dates: 2021-032021-05
 Publication Status: Published in print
 Pages: -
 Publishing info: -
 Table of Contents: -
 Rev. Type: -
 Identifiers: DOI: 10.1016/j.brs.2021.02.019
 Degree: -

Event

show

Legal Case

show

Project information

show

Source 1

show
hide
Title: Brain Stimulation
  Abbreviation : Brain Stimul
Source Genre: Journal
 Creator(s):
Affiliations:
Publ. Info: New York, NY : Elsevier
Pages: - Volume / Issue: 14 (3) Sequence Number: - Start / End Page: 488 - 497 Identifier: ISSN: 1935-861X
CoNE: https://pure.mpg.de/cone/journals/resource/1935-861X