FSL-BASED HYBRID ATLAS PROMOTES ACTIVATION WEIGHTED VECTOR ANALYSIS IN FUNCTIONAL NEURORADIOLOGY

The hybrid atlas is the outcome of the joint operation between different brain templates found into the FMRIB Software Library. They are Juelich histological atlas and Harvard-Oxford cortical and subcortical structural atlases. Both are probabilistic labelled and registered in MNI152 space. Juelich model was created by averaging multi-subject post-mortem cyto and myelo-architectonic segmentations, which has detected 52 grey matter structures and 10 white matters ones. Harvard-Oxford models cover 48 cortical and 21 subcortical structural regions, computed by segmentation of T1-weighted images of healthy male and female. The joint process was possible choosing a reference atlas and then adding lacking anatomical structures. In our case, Juelich atlas was the template from which regions dearth were easily included choosing them from Harvard-Oxford atlases. This procedure, shaped with complete or partial union operations, gives rise to an hybrid atlas that covers 161 regions, in which 121 are the 100% of Juelich, and other 40 are a variable percentage of Harvard-Oxford original brain volumes. The benefits of this hybrid atlas are the integration of fundamental neuroanatomy models useful for co-registration that in the standard template were absent, e.g. many frontal and temporal cortexes, subcallosal portions, cingulate gyrus and thalamus halves.