[MINC-users] determinant of non-linear local deformation fields

[Marc BOUFFARD]

Hello,

I have a question about deformation grids obtained from non-linear
registration using nlpfit.  These grids contain the 3D displacements at
each voxel applied to the source to match the template or to the template
to match the source?

Now if the determinant is calculated from those grids with mincblob and it
is found that voxel x has a value greater than 1.  Does this mean the
region in the neighborhood of x has expanded relative to the source  or
relative to the target?

In a further step, to obtain modulated VBM data should the standard VBM
data be multiplied by the determinant of the Jacobian matrix or its
inverse?