Configuring Epilepsy Analysis

From MEG Core
Revision as of 10:57, 19 November 2019 by Jstout (talk | contribs)
Jump to navigation Jump to search


After installing and configuring the analysis machine:

Configuration Files

 default.dip : used as input to the dipoleFit and dfit programs as the default starting options for dipole fit
 processing.cfg : used to preprocess the data for viewing
 channelset.cfg : Montage Creation (ordering channels is done through virtual channels) : Virtual Channel Creation

Configuring Data Editor Layout

Configurations are stored in the ChannelSet.cfg file. Current Montages Include:

  • MEG_LCR_22
  • MEG_LCR_22_EEG_LCR_21
  • EEG_

Creating a View Montage

The data editor layout orders the channels by acquisition order and may not be preferred
To create ordered channels, a virtual channel dataset will need to be created

 DataEditor >> Edit >> Virtual Channels
 Select a virtual channel and add to Plus Box >> Name the new channel (it must be different from acquisition names - choose lowercase or uppercase as a workaround)
 Save the virtual channel .vg file to $HOME/.meg/resources/

Head Model

Preferred Method - Multisphere model from inner skull approximation

 orthohull  #Realigns the MRI to match the MEG subject head space (origin is midpoint between LPA/RPA and other axis runs through the nasion)
 #Also creates an inner skull approximation using the inflated/smoothed brain surface
 localSperes -d $Dataset -s multisphere.shape 

Manual Method - Single Shell based on scalp

 MRIConvert   >> imports mri into ctf format
 MRIViewer -mri CTF.mri >> creates headshape and headmodel >> save to default.hdm
 Dipolefit -hdm default.hdm

Dipole Fit

 Set the time, epoch, and duration of dipole fit
 Commandline dipole fit
 dfit -a -z -b -0.010 -e 0.010 -h $ds_Filename/default.hdm -f default.dip -m $MarkerName $ds_Filename  Output

Processing Pipeline

check tags >> cat anat+ortho.HEAD | grep TAGSET_LABELS 3dtagalign << << creates an average head position changeHeadPos << rewrites the head position