Hi. Sure - you can try this - though I have no idea whether there will be
sufficient information in this cut-down ROI of the eye to robustly find
motion parameters. Yes - you can easily use avwroi - you want to specify a
3D ROI which will turn a 3D image into a 3D ROI or a 4D image into a
cut-down 4D image. So use:
avwroi <input> <output> <xmin> <xsize> <ymin> <ysize> <zmin> <zsize>
Thanks, Steve.
On Thu, 28 Nov 2002, Arun Bokde wrote:
> Hello FSLers,
>
> A recent paper (Tregellas J et al, HBM, vol 17: 237-243) shows that a
> measure of eye movement can be obtained by using the standard EPI
> sequences. I am interested in trying it out using FLIRT, as the method
> described basically is a rigid body registration process on the time
> series of each eye. Is there any reason that FLIRT would have problems
> with a time series file that has perhaps 10 x 10 voxels per slice and
> 4-5 slices ? Is there a program that could produce a 4D avw file from
> another 4D avw file based on an ROI ? I was looking at avwroi but the
> help info is not very clear to me.
>
> TIA
>
> Cheers, Arun
>
Stephen M. Smith
Head of Image Analysis, FMRIB
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
