Tract-Based Spatial Statistics: Voxelwise Analysis of Multi-Subject Diffusion Data
Smith S, Jenkinson M, Johansen-Berg H, Rueckert D, Nichols T, Mackay C, Ciccarelli O, Watkins K, Cader M, Bartsch A, Matthews P, Behrens T
Many imaging studies are using DTI data in voxelwise (VBM-style) analyses in order to localise brain change related to development, degeneration and disease. However, there has not been a satisfactory solution to the question of how to align FA images from multiple subjects in a way that allows valid conclusions to be drawn from the subsequent voxelwise analysis. Furthermore, the arbitrariness of the spatial smoothing extent has not yet been resolved. We present a method, Tract-Based Spatial Statistics (TBSS), that aims to solve these issues via nonlinear registration followed by projection onto an alignment-invariant tract representation (the mean FA skeleton).