This paper describes DARTEL, which is an algorithm for diffeomorphic image registration.
It is implemented for both 2D and 3D image registration and has been formulated to
include an option for estimating inverse consistent deformations. Nonlinear registration
is considered as a local optimisation problem, which is solved using a Levenberg-Marquardt
strategy. The necessary matrix solutions are obtained in reasonable time using a multigrid
method. A constant Eulerian velocity framework is used, which allows a rapid scaling
and squaring method to be used in the computations. DARTEL has been applied to intersubject
registration of 471 whole brain images, and the resulting deformations were evaluated
in terms of how well they encode the shape information necessary to separate male
and female subjects and to predict the ages of the subjects.