Dear all,
Could anyone explain how sampling FA via tcksample is comparable to averaging FA within a binary mask of a tract? Tcksample computes FA along each streamline of a tract, but is the FA weighted by any feature such as streamline density?
I am asking because while tcksample gives me left-lateralized FA values of a given tract, averaging FA across tract volume gives me a completely opposite laterality pattern of the same tract. This is the case for some tracts but not all.
Is there any research done on comparing along-tract microstructural analysis to simple volume averaging?
Thank you for any suggestions,
Dominika