Diedrichsen J (2006) A spatially unbiased atlas template of the
human cerebellum. NeuroImage 33:127-38.
Abstract This article presents a new
high-resolution atlas template of the human cerebellum and brainstem, based on
the anatomy of 20 young healthy individuals. The atlas is spatially unbiased,
i.e. the location of each structure is equal to the expected location of that
structure across individuals in MNI space, a result that is cross-validated
with an independent sample of 16 individuals. At the same time, the new
template preserves the anatomical detail of cerebellar structures through a
nonlinear atlasgeneration algorithm. In comparison to current whole-brain
templates it allows for an improved voxel-by-voxel normalization for functional
MRI and lesion analysis. Alignment to the template requires that the cerebellum
and brainstem are isolated from the surrounding tissue, a process for which an
automated algorithm has been developed. Compared to normalization to the MNI
whole-brain template, the new method strongly improves the alignment of
individual fissures, reducing their spatial spread by 60%, and improves the
overlap of the deep cerebellar nuclei. Applied to functional MRI data, the new
normalization technique leads to a 5-15% increase in peak t-values and in the
activated volume in the cerebellar cortex for movement vs. rest contrasts. This
indicates that the new template significantly improves the overlap of
functionally equivalent cerebellar regions across individuals. The template and
software are freely available as an SPM-toolbox, which also allows users to
relate the new template to the annotated volumetric (Schmahmann et al., 2000)
and surface-based (Van Essen, 2002a) atlas of one individual, the
colin27-brain.
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