Dear Freesurfer experts,
I would like to calculate the mean distance from cortex to the scalp in a region of interest (the area under the stimulator), to investigate the influence of this distance on tDCS effects. A similar question was asked in the archives, and the use of mris_distance_transform was suggested.
I am new to freesurfer, and I wasn't able to figure out if this approach is suitable for me and, if yes, what files I need to load in. I checked mris_distance_transform -help, yet I am still missing some parts. Could you point me to the right direction?
As <label>, can I load in the ROI of the area under the scalp electrode?
I tried to run the function with lh.pial and the lh.BA45.label just to see how it works, and I also have questions concenring the output:
mris_distance_transform surf/lh.pial label/lh.BA45_exvivo.label unsigned lh.dist writing surface values to surf/lh.dist.w. avg = 101.288, stdev = 50.852, min = 0.206, max = 207.610 distance transform took 0.1 minutes
How can I view the output file lh.dist.w.? And what do the values mean (is it by any chance already the mean distance from the surface to the label I am looking for, and if yes, what is the dimension)?
Any suggestions would be highly appreciated! Many thanks!
Lucia