Localization of intracranial electrodes is critical for invasive epilepsy evaluations and to confirm or not confirm the epileptic zone hypothesis. Various methods exist using various open-source and commercial software. Here is one method using some latest updates to the Brainstorm software.
Required imaging:
- Pre-implantation T1 without contrast 1mm 3D volume scan
- Post-implantation CT scan without contrast 1mm 3D volume scan
Assuming you are already familiar with Brainstorm and have already created anatomy files using Freesurfer:
Import Freesurfer anatomy
Choose Freesurfer folder
Change file type to Freesurfer
Set fiducial points & compute MNI coordinates
Convert CT to .nii.gz first with MRIcroGL (drag and drop)
Import CT by selecting ‘Import MRI’
Select the CT .nii file
Apply transformation
Register on default MRI
CT overlay in MRI Viewer
Import ECOG data
Edit channel file
Change channel type to ECOG
Go to CT, Display, Overlay on default MRI (MRI Viewer)
Right click, Electrodes, Set electrode position
View in 3D
http://neuroimage.usc.edu/brainstorm/