Hi - did you make sure that the mask image was set to the standard
space reference image used in your registrations, and that the mm co-
ordinates were in the space of this image? Also, is it possible that
the registration had failed for the problematic FEAT runs, or that
the voxel you specified was outside the field-of-view of those datasets?
Cheers, Steve.
On 31 Mar 2007, at 21:37, Sang Lee wrote:
> Dear FSL user,
>
> I am using PE files to calculate the percentage signal change via
> featquery for a single voxel for
> each of my subjects (total n = 28).
>
> Given that I am using PE file, an anatomical mask, and a mm
> coordinate for a single voxel, using
> featquery tool with convert PE/COPE to % signal change option
> turned on, I should get % signal
> change for each of my subjects for that single voxel.
>
> However, several of the subjects report file comes out with a
> coordinate that I did not specify.
>
> For example, I specified (-16 -4 -16) for my mm coordinates.
> However, several of my subjects'
> report file comes out with % signal change values with the
> following coordinate (90 -126 -72).
> This happens with one third of my subjects. Is there something that
> I am doing wrong? How do I
> deal with those results with the coordinates that I did not specify?
>
> I am trying to plot mean % signal change plot for all 28 subjects,
> but I am not sure what to do with
> those subejct's mean % signal change that comes out with a
> coordinate that I did not specify.
>
> Any input would be a great help!
>
> Thank you in advance.
>
> From Sang
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Stephen M. Smith, Professor of Biomedical Engineering
Associate Director, Oxford University FMRIB Centre
FMRIB, JR Hospital, Headington, Oxford OX3 9DU, UK
+44 (0) 1865 222726 (fax 222717)
[log in to unmask] http://www.fmrib.ox.ac.uk/~steve
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