Fig. 2.

ROI-based versus surface vertex-wise approach as implemented in FreeSurfer. ROI-based approach depicting the lateral part of the right hemisphere with Desikan-Kiliany atlas regions (left) and surface vertex-wise approach (right) for statistical analysis of clinical developmental sMRI data. The hemisphere is inflated for a better view of gyri and sulci. The blue area on the right picture highlights a region with significant differences in cortical thickness between two groups, which falls partly into pars triangularis and rostral middle frontal cortex as indicated by Desikan-Kiliany atlas region outlines. Using the ROI-based approach this difference may or may not contribute to significant cortical thickness differences in the rostral middle frontal cortex, pars triangularis, or pars opercularis without the possibility of localizing the area more precisely. OP = pars opercularis; RMF = rostral middle frontal cortex; PT = pars triangularis