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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