Thanks Steve for that information.
Another quick question:
When one runs siena, does the program expect the first image to be the
"prior MRI" and the
second one to be the "current MRI" ? that is should the command line be:
siena prior_MRI current_MRI
Or does it not matter ? I tried to look for this issue on the Siena
webpage but I could find this information.
Thanks
Mehul
On Wed, Oct 7, 2009 at 11:51 PM, Stephen Smith <[log in to unmask]> wrote:
> Hi - the main difference is a different version of the segmentation. There
> is no 'fundamental' change in the way SIENA works, but yes I would expect
> the 'noise' on the estimation to be different. So any individual subject
> results may be a bit different, but bottom-line results (e.g. correlation
> with other variables) should not fundamentally be different. So - yes,
> worth using the new version (the segmentation should be more robust under a
> wider range of conditions) but if you have a huge dataset already mostly
> analysed with the old SIENA you could complete the study using the older
> version. Probably just to be safe it's best not to mix versions within one
> study.
> Cheers.
>
> On 8 Oct 2009, at 05:49, Mehul Sampat wrote:
>
> Hi Folks,
>
> In the past we have used Siena version 2.4 and recently we got the
> updated version of fsl and siena (siena version 2.6).
> I re-ran some cases with Siena v2.6 and the results are different.
>
> Is it fair to say that we should put more faith in the values obtained
> with Siena version 2.6 and re-analyze the cases we had processed
> with Siena version 2.4 ?
>
> Thanks
> Mehul
>
>
>
> ---------------------------------------------------------------------------
> 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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