Hi,
This sounds ok. SIENA estimated shift to subvoxel accuracy using an
extended profile perpendicular to the edge. When further regularised
via a) smoothing and b) cross-subject averaging then yes this sounds
reasonable.
Cheers.
On 12 Sep 2007, at 16:28, Matthew Kempton wrote:
> Dear SIENA users,
>
> Thanks for the information Steve, I have now obtained the correct flow
> values.
> However I have noticed that they are still quite small.
>
> From our experiment we expect only a small change in boundary
> shifts. For
> seven subjects we had a peak mean flow value of 0.1mm (SD=0.01 mm)
> in the
> lateral ventricle. Although this is highly significant, is SIENA
> really
> able to be sensitive to such a small change (original MRI voxel
> size was
> 0.94 x 0.94 x 1.5mm).
>
>
> Thanks,
>
> Matthew
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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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