Hi David,
If it looks like the EPIs would need very different scalings in the
different directions to fit the structurals then it probably means that
one or other have the voxel resolution set not quite right. You might be
able to fix this by changed 7DOF to 9 or 12.
Cheers, Steve.
On Thu, 24 Jul 2003, Glahn, David wrote:
> Hello Everyone,
>
> I ran a group of about 20 subjects this week and have noticed that between
> 35 and 50% of the cases have a significant misalignment when spatially
> normalizing the EPI image to the higher resolution image. The model
> selected via the FEAT interface used 7 DOF and normal search. The
> misalignment was the same for these subjects, an elongation of the
> functional image in the posterior regions (occipital cortex). Any ideas on
> what is going on?
>
> Best,
>
> David
> _______________________
> David Glahn, Ph.D.
> Department of Psychiatry and Research Imaging Center
> University of Texas Health Science Center at San Antonio
> Voice (210) 567-5508
> Fax (210) 567-1291
>
Stephen M. Smith MA DPhil CEng MIEE
Associate Director, FMRIB and Analysis Research Coordinator
Oxford University Centre for Functional MRI of the Brain
John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK
+44 (0) 1865 222726 (fax 222717)
[log in to unmask] http://www.fmrib.ox.ac.uk/~steve
|