Hi @jdtournier, Thank you so much for your answer. I have 43 Parkinson’s disease (PD) patients and I created a **FOD population template** using these patients. I want to reconstruct some basal ganglia pathways using this template (I am using the template because the study design includes the analysis of PD patients as a group).

I am assuming that the reconstructed pathways would be, in some way, representative of all those PD patients. Then I would like to 1.- quantify the streamlines count (or sum of streamline weights using SIFT2), 2.- compare the streamline count between different basal ganglia pathways and 3.- correlate the streamlines count with some clinical information. As you pointed out, using SIFT, I am assuming that the streamline count would have a biological significance taking into account the white matter degeneration occurring in PD patients.

Thank you so much for your help!!