Robustifying Probabilistic Tractography by Using Track Orientation Distributions

Thijs Dhollander¹, ², Louise Emsell¹, ³, Wim Van Hecke¹, Frederik Maes¹, ², Stefan Sunaert¹, ³, Paul Suetens¹, ²

We propose to extend the concept of track-density imaging (TDI) to also encode the angular distribution of a dense full-brain short-tracks tractogram. Similarly to the fiber orientation distribution (FOD), the resulting track orientation distribution (TOD) in each voxel has peaks in the general directions of white matter pathways. As such, the TOD can be used anew to generate a short-tracks tractogram, yielding another TOD. We explore the meaning and effectiveness of using these TODs for (targeted) tractography. We show that, by inherently "planning ahead", the TODs are able to guide the tractography process much more robustly.