I also thought about yet another possibility. If you want to avoid any
spatial distortion related to registration, you might want to consider
using anatomical landamark registration as implemented in Fressurfer and
then you can use different parcellation methods. I don't know much about
this method but what I know is that you brains must be in a good state, eg:
no lesions or other "natural distortions" ie healthy good quality brains,
another thing is that this registration is quite computationally gready and
takes a lot of time. I don't know if it could be of any help for you?
Iwo
On Aug 8 2011, [log in to unmask] wrote:
> Hello Iwo,
>
>> > I've different acquisitions: For example, one structural volume
>> > (created with an MP Rage sequence) with a relative high resolution.
>> > But I also have some EPI images with a lower spatial resolution, 3x3x5
>> > ... from this/these 3-dimensional blocks, I want to choose an
>> > ellipsoid/are/ROI, which contains mainly the region of the V1... In
>> > 3DSlicer there is an modul/option to create a 3D Boxed ROI, but as I
>> > understand, it was just for visualization, and no possibility to
>> > export the mask to nifti.
>>
>> Is there any specific reason you don't want to do any registration? e.g
>> either EPIs to an EPI template, or to your structural/template? If you
>> could register your EPI/structurals, then you could use an atlas roi for
>> V1? It would be more realistic representation of the actual V1? What is
>> the purpose of using ROIs in your study?
>
> It depends on what you mean with registration... I don't want to
> normalize the data to a standard space (for example MNI-Template)... ...
> and I don't want to "wrap", "translate", whatever "manipulate" the data
> in this way...
>
> maybe the other way round may be possible somewho? wrapping a
> V1-representation of wfu_pickatlas to my data?
>
>Thanks
>
>Andreas
>
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--
Iwo
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