Hi,
It's one way of 'warping' the results from the actual edges (after
transformation into standard space) onto the MNI152 standard space
brain edges, in order to allow comparison across subjects. The warping
is effectively nearest-neighbour interpolation, i.e. is keeping the
flow values exactly unchanged, just shifting their positions.
The Gaussian smoothing, as ever in such voxelwise analyses, is
optionally (and arbitrarily) applied in order to boost SNR.
Cheers, Steve.
On 26 Feb 2008, at 11:15, Antonios - Constantine Thanellas wrote:
> Dear fsl users,
>
> I would like to ask why there's a need to dilate the flow images and
> thicken
> their edges? in this way we create an artificial change which does not
> correspond to the real change.right?
> What about the gaussian smoothing?why do we need to smooth the flow
> images?
>
> Thank you
> Antonios-Constantine Thanellas
>
---------------------------------------------------------------------------
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
---------------------------------------------------------------------------
|