Tractometry of the subcortical motor network using SHORE- based indices

Introduction. In this work we investigated the 3D-SHORE numerical indices for quantitative tractography in the sub-cortical motor network (SC-MN). Using DSI we reconstructed the network connections and compared the outcomes about white matter (WM) density and structure to those provided by GFA and MTR. Methods. Ten healthy subjects (age 56.1±17.8 years old, mean±SD) went through a DSI scan twice one month apart (± 1 week, tp1c and tp2c, see [1] for more details). The Ensemble Average Propagator (EAP) was reconstructed using the SHORE model and the orientational (ODF) and microstructural indices were derived including Return to zero (RTOP), Return to axis (RTAP) and Return to plan (RTPP) probability and propagator anisotropy (PA). These provide an estimation of the mean pore geometry (volume, cross-section, length, diameter), irrespectively of the pore shape. SHORE indices were extracted for each fiber bundle.