I am interested in the SPM5 preprocessing option 'unwarp'. Could you please tell me why you decided to use it? Did you normalize your images or would that be redundant when you use unwarp?
Julie E. McEntee, M.A., C.C.R.P.
Senior Research Program Coordinator
Department of Psychiatry- Neuroimaging
Johns Hopkins University School of Medicine
600 N. Wolfe St./ Phipps 300
Baltimore, MD 21287
----- Original Message -----
From: "Dr. Karsten Mueller" <[log in to unmask]>
Date: Tuesday, July 8, 2008 5:08 am
Subject: [SPM] pixdim4 in NIfTI header after realign_anbd_unwarp.m
To: [log in to unmask]
> Dear Colleagues,
> we are using Realign and Unwarp (spm_realign.m, spm_uw_estimate.m, and
> spm_uw_apply.m) with 4D-NIfTI data which gives very nice results.
> However, these m-routines seem to change the NIfTI-header. Before
> starting the realignment, our header shows
> time_units ms
> pixdim4 2000.0000000000
> which is correct. After using realign and unwarp, the NIfTI header shows
> time_units s
> pixdim4 1.0000000000
> This might be a problem when further programs are using the repetition
> time from the NIfTI header.
> With best wishes,