Dear Rachel:
Yes you can do exactly this. The following sequence of steps has been generally
recommended in the past:. (note I don't include slice timing correction which
should be done before step one if appropriate to your design).
1) realign functionals to some common functional image if possible. Write out a
mean image but don't reslice functionals at this point.
2) coregister T1 to the mean functional image. Don't write out a new T1 image at
this point.
3) Normalize the T1.
4) apply the normalization parameters from the T1 to your functional volumes-
this will reslice the functionals. (make sure you set the normalization defaults
to allow you to choose the voxel size of the functional images).
You should now have normalized T1 and functional images. Assuming good quality
T1 images from subjects with reasonably normal brains, and good coregistration
between T1 and functionals you should have minimal distortions (or no more than
were there originally).
HTH,
Darren
Rachael Seidler wrote:
> Hello all,
> I'm having a problem normalizing some mri functional images that contain
> distortions. Specifically, there is no visible data in the inf. frontal
> region of these images.. When I normalize them to the epi template however,
> everything gets stretched forward to fill in the empty space. I suspect
> this distorts the signal outside of the original distortion region. Is
> there a way to normalize anatomical images to the standardized space, and
> then apply these parameters to the functional data? Or can anyone recommend
> another fix?
> Thanks in advance,
> Rachael
> Rachael D. Seidler, PhD
> University of Minnesota Dept of Neuroscience
> and Brain Sciences Center, 11B
> Veterans Affairs Medical Center
> One Veterans Drive
> Minneapolis, MN 55417
> Phone: 612 725-2000 x.1765
> Fax: 612 725-2291
> Email: [log in to unmask]
> _________________________________________________________________________
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Darren R. Gitelman, M.D. E-mail: [log in to unmask]
Cognitive Neurology and Voice: (312) 908-9023
the Alzheimer¹s Disease Center Fax: (312) 908-8789
http://www.brain.nwu.edu
Northwestern Univ., 320 E. Superior St., Searle 11-470, Chicago, IL 60611
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