Dear Lily,
A NIfTI file can only store a single voxel-to-world affine
transformation for all the volumes of a 4D file. An extra .mat file is
sometimes used by SPM (e.g. with realignment) to store a different
transformation for each volume. This is something checked by
spm_check_orientation hence the different outcome whether that file was
present or not.
Best regards,
Guillaume.
On 27/08/2021 17:18, Lily T wrote:
> Thanks, Guillaume and John for the quick replies! It turns out the .mat file was the key. I apologize if I missed something, but what is the significance of the .mat file in relation to spm_check_orientations?
>
> Thanks!
> Lily
>
--
Guillaume Flandin, PhD
Wellcome Centre for Human Neuroimaging
UCL Queen Square Institute of Neurology
London WC1N 3BG
|