I realize questions as basic as how to get coregistration to work are a
few notches below what usually gets answered on this list, but I'm
really at my wits end here.
The problem is that 4 (out of 27) of my subjects plainly refuses to have
their T1 images coregistered to the mean EPI image, or any other EPI
image for that matter. The experiment totals 4 runs, and I've tried to
coregister the T1 to all of the mean images post- realignment, as well
as multiple ordinary, realigned, images. I've also tried to coregister
the EPI's to the T1, once again without success.
I've attached the coreg output files for all 4 subjects. As you can see
they all seem to be out of alignment in the Z- dimension, with the T1
consisently lower than the EPI's, while otherwise seemingly in OK
I've tried fiddling around with the settings, changing objective
functions, seperation and tolerances without much success. I've also
tried using the coregister and reslice function, with interpolations
from trilinear up to 7th degree spline- again without success. This is
rather troublesome as this means that the normalization parameters
calculated by the unified segementation procedure are similarly shifted,
which results in "extracranial" activations, when overlaid on the
Can anyone give me a clue as to why this happens, and how to fix or work
I'm on a Vista x64 workstation using Matlab R2007b, and SPM 8b r2598.
Haakon G. Engen
University of Oslo