Dear Volker,
If I am not mistaken, the "seed_to_target" images are from using classification targets, which it appears you are not doing. It is unclear whether you are confused about this or the reviewer may be confused about the methods used.
If you are using one seed mask and one waypoint/termination mask then from the FSL website:
waytotal - a text file containing a single number corresponding to the total number of generated tracts that have not been rejected by inclusion/exclusion mask criteria.
So it seems 'waytotal' would be the relevant determinant of connection strength. You should have a waytotal for each exclusive 1-seed-1-waypoint tractography run.
Hope this helps,
Dustin
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From: FSL - FMRIB's Software Library [[log in to unmask]] On Behalf Of Volker Baur [[log in to unmask]]
Sent: Friday, May 11, 2012 9:44 AM
To: [log in to unmask]
Subject: [FSL] connection strength after probtrackx
Dear experts,
a reviewer had a suggestion for us how to assess the connection strength for a particular pathway identified with probtrackx.
"It is possible to determine how many of all emitted tracing samples reached the target (summing the voxel values in FSL over the "seed_to_target" images with the relevant option in FSL), and this measure is sometimes used as a determinant of connection strength."
Perhaps someone of you can explain in what way is this proposed connection measure different from the values stored in "waytotal"?
For tractography we used a seed mask, and one waypoint/termination mask.
Thanks for any help,
Volker
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