Hi FSL community,
I'm trying to obtain a connectivity matrix from a whole brain tractography using probtrackx. I used the --network option and I obtained a fdt_network_matrix 82x82 using cortical and subcortical volumes (from freesurfer parcellation) . As I read in this mailing list, I normalized it dividing each row of the matrix by the corrisponding waytotal.
I have some questions:
1) Is it correct to normalize by waytotal or should I do it by the sum/average of volumes of the connecting regions too?
2) I tried to correct the path distribution by the distance between regions using the --pd option (mantaining the --network) but I verified that the fdt_network_matrix and waytotal remain the same as them without correction. Is it correct?
3) How can I obtain a connectivity matrix corrected by the distance between regions?
4) finally, my fdt_network matrix is not symmetric. In order to analyze it, after normalization, is it correct to symmetrise it averaging the symmetrical elements?
I attach my probtrackx.log, fdt_network_matrix and the waytotal file.
Thank you a lot.
Elisabetta
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