Hi,
It is not unusual to see some stretching outside of the brain.
As long as the regions inside the brain are well aligned then the stretching outside can be ignored.
We would encourage you to use a fieldmap though as, in our experience, the registration (as evaluated inside the brain) is likely to be improved.
All the best,
Mark
On 9 Sep 2014, at 22:32, Andrej Schoeke <[log in to unmask]> wrote:
> Hello,
>
> in a current analysis, we had some activity that was clearly outside the
> brain, but it was obvious that it belongs to structures close by. We
> thought that better registration could improve the results.
>
> We tried BBR (func to highres) and nonlinear 12 dof, 10mm warp
> resolution (highres to standard). We are very satisfied with the
> separate reg results. However, the end result of func to standard shows
> that a segment of func is lying outside the registered areas. It seems
> that the registrations takes place before smoothing and that this step
> could result in the described effect. We tried also applying a field
> map, but the result did not change.
>
> Here is a link to to an example_func2standard picture:
> http://i.imgur.com/Jc6CBRJ.png
>
> Is this results avoidable (e.g. reduce smoothing, better registration),
> just a byproduct or maybe even normal?
>
> I would appreciate your input.
>
> Thank you,
> Andrej
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