afni.nimh.nih.gov

3dUniformize does non-uniformity correction on an AFNI dataset. This paper helps explain what non-uniformity correction means:

[pet.med.va.gov]

To me, it is "intensity drift" -- a problem that confounds segmentation software like SureFit and FreeSurfer.

If you want to know the gory details of what this utility does, I found the commends in the source code pretty helpful:

[afni.nimh.nih.gov]

Donna Hanlon
Van Essen Lab, Wash U