Development and testing of implanted carbon electrodes for electromagnetic field mapping during neuromodulation

Neeta Ashok Kumar, Munish Chauhan, Sri Kirthi Kandala, Sung Min Sohn, Rosalind J. Sadleir

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


Purpose: Deep brain stimulation electrodes composed of carbon fibers were tested as a means of administering and imaging magnetic resonance electrical impedance tomography (MREIT) currents. Artifacts and heating properties of custom carbon-fiber deep brain stimulation (DBS) electrodes were compared with those produced with standard DBS electrodes. Methods: Electrodes were constructed from multiple strands of 7-μm carbon-fiber stock. The insulated carbon electrodes were matched to DBS electrode diameter and contact areas. Images of DBS and carbon electrodes were collected with and without current flow and were compared in terms of artifact and thermal effects in phantoms or tissue samples in 7T imaging conditions. Effects on magnetic flux density and current density distributions were also assessed. Results: Carbon electrodes produced magnitude artifacts with smaller FWHM values compared to the magnitude artifacts around DBS electrodes in spin echo and gradient echo imaging protocols. DBS electrodes appeared 269% larger than actual size in gradient echo images, in sharp contrast to the negligible artifact observed in diameter-matched carbon electrodes. As expected, larger temperature changes were observed near DBS electrodes during extended RF excitations compared with carbon electrodes in the same phantom. Magnitudes and distribution of magnetic flux density and current density reconstructions were comparable for carbon and DBS electrodes. Conclusion: Carbon electrodes may offer a safer, MR-compatible method for administering neuromodulation currents. Use of carbon-fiber electrodes should allow imaging of structures close to electrodes, potentially allowing better targeting, electrode position revision, and the facilitation of functional imaging near electrodes during neuromodulation.

Original languageEnglish (US)
Pages (from-to)2103-2116
Number of pages14
JournalMagnetic Resonance in Medicine
Issue number4
StatePublished - Oct 1 2020


  • MR image artifact
  • MR safety
  • carbon electrodes
  • deep brain stimulation
  • magnetic resonance electrical impedance tomography
  • neuromodulation

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging


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