I ran all 4 steps of TBSS with the 4th step being: tbss_4_prestats 0.2

When I open the images in the stats folder, say all_FA_skeletonized and check the histogram, I get some intensity values  < 0.2. (Image attached)

Is that normal? Do I still have to explicitly threshold this to remove the Partial Volume voxels. I assumed the threshold of 0.2 should remove everything under 0.2. 

Thanks. 

- Anita