Localization of dense intracranial electrode arrays using magnetic resonance imaging. Neuroimage 2012 Oct 15;63(1):157-165
Date
07/05/2012Pubmed ID
22759995Pubmed Central ID
PMC4408869DOI
10.1016/j.neuroimage.2012.06.039Scopus ID
2-s2.0-84864396812 (requires institutional sign-in at Scopus site) 90 CitationsAbstract
Intracranial electrode arrays are routinely used in the pre-surgical evaluation of patients with medically refractory epilepsy, and recordings from these electrodes have been increasingly employed in human cognitive neurophysiology due to their high spatial and temporal resolution. For both researchers and clinicians, it is critical to localize electrode positions relative to the subject-specific neuroanatomy. In many centers, a post-implantation MRI is utilized for electrode detection because of its higher sensitivity for surgical complications and the absence of radiation. However, magnetic susceptibility artifacts surrounding each electrode prohibit unambiguous detection of individual electrodes, especially those that are embedded within dense grid arrays. Here, we present an efficient method to accurately localize intracranial electrode arrays based on pre- and post-implantation MR images that incorporates array geometry and the individual's cortical surface. Electrodes are directly visualized relative to the underlying gyral anatomy of the reconstructed cortical surface of individual patients. Validation of this approach shows high spatial accuracy of the localized electrode positions (mean of 0.96 mm ± 0.81 mm for 271 electrodes across 8 patients). Minimal user input, short processing time, and utilization of radiation-free imaging are strong incentives to incorporate quantitatively accurate localization of intracranial electrode arrays with MRI for research and clinical purposes. Co-registration to a standard brain atlas further allows inter-subject comparisons and relation of intracranial EEG findings to the larger body of neuroimaging literature.
Author List
Yang AI, Wang X, Doyle WK, Halgren E, Carlson C, Belcher TL, Cash SS, Devinsky O, Thesen TAuthor
Chad Carlson MD Interim Chair, Professor in the Neurology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AlgorithmsArtifacts
Brain
Electrodes, Implanted
Electroencephalography
Humans
Image Enhancement
Image Interpretation, Computer-Assisted
Magnetic Resonance Imaging
Pattern Recognition, Automated
Reproducibility of Results
Sensitivity and Specificity
