[FieldTrip] obtaining voxel locations

[Mohsen moradi]

*Hello,** *

       I am mohsen alimoradi, MSc student of artificial intelligence
in Qazvin Azad University. *
   **I am working on  the Biomag 2012 analysis competition.**
   I have downloaded a .zip file from
ftp://ftp.fcdonders.nl/pub/biomag2012/.
<ftp://ftp.fcdonders.nl/pub/biomag2012/>** **   I have extracted the
content and I am interested in the second objective,**   the one
related to long-term memory representations (folder data2).** **   I
was able to load the 2 mat files into Matlab workspace.** **   I was
also able to use FieldTrip functions on tutorial code.** **   How
could I use FieldTrip on this data? If there are more ways, which one
would be the fastest/easiest?** **   Thanks a lot

*



On Tue, Jul 9, 2013 at 8:44 PM, Robin <robince at gmail.com> wrote:

> I was wondering how to get the voxel positions (or origin and voxel size)
> for a fieltrip mri structure.
>
> I have an anatomical scan which I have normalised to the T1 brain:
>
> >> mrin
>
> mrin =
>
>       anatomy: [181x217x181 double]
>     transform: [4x4 double]
>           dim: [181 217 181]
>        params: [1x1 struct]
>       initial: [4x4 double]
>      coordsys: 'spm'
>           cfg: [1x1 struct]
>
> I can I obtain the location of any voxel in MNI coordinates (mm or cm)?
> When loading a Nifti file (with load_nii) I can find origin and voxel_size
> with:
>
> voxel_size = abs(nii.hdr.dime.pixdim(2:4));        % vol in mm
> origin = round(abs(nii.hdr.hist.originator(1:3)));
>
> and then posmm = (vox-origin) .* voxel_size. Is there any way to do the
> same from the fieldtrip structure? I can't find the corresponding header
> information.
>
> Thanks
>
> Robin
>
> _______________________________________________
> fieldtrip mailing list
> fieldtrip at donders.ru.nl
> http://mailman.science.ru.nl/mailman/listinfo/fieldtrip
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.science.ru.nl/pipermail/fieldtrip/attachments/20130710/7b68f90a/attachment-0002.html>