A unified statistical approach to deformation-based morphometry

We present a unified statistical framework for analyzing temporally varying brain morphology using the 3D displacement vector field from a nonlinear d eformation required to register a subject's brain to an atlas brain. The un ification comes from a single model for structural change, rather than two separate models, one for displacement and one for volume changes. The displ acement velocity field rather than the displacement itself is used to set u p a linear model to account for temporal variations. By introducing the rat e of the Jacobian change of the deformation, the local volume change at eac h voxel can be computed and used to measure possible brain tissue growth or loss. We have applied this method to detecting regions of a morphological change in a group of children and adolescents. Using structural magnetic re sonance images for 28 children and adolescents taken at different time inte rvals, we demonstrate how this method works. (C) 2001 Academic Press.