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Hello,


I am using the isosurface() function in order to create a mesh based on the 
T1.mgz and on the ribbon.mgz. I need those meshes for the coregistration of 
some channels.


After coregistration I do project the channels onto the cortex and extract the 
corresponding voxel coordinates. Until here, everything works fine.

Next, I am using MRIwrite in order to save the T1.mgz as *.nii.mgz which I am 
using to generate a deformation field with SPM12 to transform the voxel 
coordinates to normalized MNI coordinates. However, when I put the voxel 
coordinates (not normalized yet) into SPM12 while displaying my generated *.nii 
image it happens that the coordinates on the right hemisphere (MNI space) are 
slightly outside of the cortex which is of course not the case on my cortex 
mesh after projection.


Now I am wondering whether there is a mismatch between the mesh and the *.nii 
image (one voxel maybe)? And whether that is introduced by MRIwrite? If so, do 
I have to shift all points of the meshes by +1 in order to get correct results 
the way I want to? If not, any ideas on where that mismatch could come from?


Thank you and kind regards,

Franziska



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