[FieldTrip] Source reconstruction with MNE problem: vol doen's fit sourcespace

Magyari, Lilla Lilla.Magyari at mpi.nl
Fri Jan 27 15:17:34 CET 2012


hi Ion,
yes, the tutorial script was written and tested in the following way:
you have to align your volume to the ctf coordinate system (doesn't 
matter what was its original coordinate system),
then reslice this re-aligned volume, then segment the resliced volume,
then re-align to talairach the resliced volume (that has been re-aligned 
to ctf before).

I hope it will work out.

Lilla

Ion Lavado wrote:
> I think the problem is in the first steps, where i used neuromag 
> coordinates... and i have to work in CTF and then to Talairach... i'll 
> try it againg.
> 
> 2012/1/27 Ion Lavado <lavado at gmail.com <mailto:lavado at gmail.com>>
> 
>     Ok, thank you for your time Arjen. This is what i've done:
> 
> 
> 
> 
> 
>     *%READ AND REALINGN*
>     mri =
>     ft_read_mri('C:\Users\ilavado\Desktop\31_CW1AFMRI_ESG_ENDIKA_SANCHEZ_GOMEZ\1_028_t1_mpr_tra_p2_iso_20110314\31_CW1AFMRI_ESG_ENDIKA_SANCHEZ_GOMEZ_20110314_001_028_t1_mpr_tra_p2_iso.img');
>     cfg = [];
>     cfg.interactive    = 'yes';
>     cfg.coordsys    = 'neuromag';
>     mri_other           = ft_volumerealign(cfg,mri);
> 
>     *%RESLICING*
>     cfg = [];
>     cfg.resolution=1;
>     cfg.dim=[256 256 256];
>     mrirs = ft_volumereslice(cfg, mri_other);
>     save mrirs;
> 
>     *%SEGMENTATION*
>     load mrirs;
>     cfg = [];
>     cfg.coordsys    = 'neuromag';
>     cfg.output={'skullstrip' 'brain'};
>     seg   = ft_volumesegment(cfg, mrirs)
>     save seg seg;
> 
>     *%REALING TO TALAIRACH*
>     load mrirs;
>     cfg=[];
>     cfg.method='interactive';
>     cfg.coordsys    = 'neuromag';
>     mri_tal=ft_volumerealign(cfg,mrirs);    *%mrirs o mri_other???*
>     save mri_tal mri_tal
> 
> 
>     seg.transform = mri_tal.transform;
>     cfg             = [];
>     cfg.filename    = 'Subject29_mri_freesurfer2';
>     cfg.filetype = 'mgz';
>     cfg.parameter   = 'anatomy';
>     ft_volumewrite(cfg, mri_tal);
> 
>     cfg.filename    = 'Subject29masked2';
>     ft_volumewrite(cfg, seg);
> 
> 
> 
>     THE I CREATE ALL THE FILES (WITH THE TUTORIAL COMMANDS) WITH
>     FREESURFER with "Subject29masked2.mgz" and
>     "Subject29_mri_freesurfer2.mgz"
>     AND HERE IN THE SOURCE MODEL IS WHERE I GET THE PROBLEM.
> 
> 
>     *%CREATE THE MESH*
>     bnd = ft_read_headshape('29_mri-oct-6-src.fif', 'format', 'mne_source');
>     figure;ft_plot_mesh(bnd);
> 
> 
>     *%CO-REGISTRATION*
>     mri_norm =
>     ft_read_mri('/home/mlizarazu/public/Exchange/Mikel/Subject29/mri/orig-nomask.mgz');
>     cfg = [];
>     cfg.method = 'interactive';
>     mri_norm_ctf = ft_volumerealign(cfg, mri_norm);
> 
> 
>     mri_norm_ctf = ft_convert_units(mri_norm_ctf, 'cm');
>     T   = mri_norm_ctf.transform*inv(mri_norm_ctf.transformorig);
>     bnd  = ft_read_headshape('29_mri-oct-6-src.fif', 'format',
>     'mne_source');
>     sourcespace = ft_convert_units(bnd, 'cm');
>     sourcespace = ft_transform_geometry(T, sourcespace);
> 
> 
>     *%VOLUME MODEL*
>     cfg           = [];
>     cfg.coordsys    = 'spm';
>     cfg.output    = {'brain'};
>     seg           = ft_volumesegment(cfg, mri_norm);
> 
>     cfg = [];
>     vol = ft_prepare_singleshell(cfg,seg);
>     vol.bnd = ft_transform_geometry(T, vol.bnd);
> 
>     *%PLOT*
>     figure;hold on;
>     ft_plot_vol(vol, 'facecolor', 'none');alpha 0.5;
>     ft_plot_mesh(sourcespace_ctf, 'edgecolor', 'none'); camlight
> 
> 
> 
> 
>     When plotting i have the problem that you see in the photos... Hope
>     we can solve this.
> 
>     Thank you.
> 
> 
> 
>     Best whises
> 
> 
>     Ion
> 
> 
> 
> 
> 
> 
> 
>     2012/1/26 Stolk, A. <a.stolk at fcdonders.ru.nl
>     <mailto:a.stolk at fcdonders.ru.nl>>
> 
>         Hi Ion,
> 
>          
> 
>         Could you specify some more details so we can reproduce your
>         bug. Preferably by including a small test script with the same
>         operations applied to the testdata (as in the tutorial).
> 
>          
> 
>         Best regards,
> 
>         Arjen
> 
> 
>         ----- "Ion Lavado" <lavado at gmail.com <mailto:lavado at gmail.com>>
>         schreef:
>          > Van: "Ion Lavado" <lavado at gmail.com <mailto:lavado at gmail.com>>
>          > Aan: "Email discussion list for the FieldTrip project"
>         <fieldtrip at donders.ru.nl <mailto:fieldtrip at donders.ru.nl>>
>          > Verzonden: Donderdag 26 januari 2012 13:39:41
>          > Onderwerp: Re: [FieldTrip] Source reconstruction with MNE
>         problem: vol doen's fit sourcespace
> 
>          >
>          > Thank you for your help. I realigned it to Tailarach prior to
>         freesurfer processing. Any idea?
> 
> 
>          >
>         Ion 
>          >
>          > 2012/1/19 Stolk, A. <a.stolk at fcdonders.ru.nl
>         <mailto:a.stolk at fcdonders.ru.nl>>
>          >
> 
>              >
> 
>             Hi Ion,
> 
>              
> 
>             Did you realign your anatomical image to Talairach space
>             (and not accidentally to MNI space) prior to the processing
>             with Freesurfer?
> 
>              
> 
>             http://imaging.mrc-cbu.cam.ac.uk/imaging/FindingCommissures
> 
>              
> 
>             Best regards,
> 
>             Arjen
> 
>              
> 
> 
>              > ----- "Ion Lavado" <lavado at gmail.com
>             <mailto:lavado at gmail.com>> schreef:
>              > > Van: "Ion Lavado" <lavado at gmail.com
>             <mailto:lavado at gmail.com>>
>              > > Aan: fieldtrip at donders.ru.nl
>             <mailto:fieldtrip at donders.ru.nl>
>              > > Verzonden: Donderdag 19 januari 2012 09:25:16
>              > > Onderwerp: [FieldTrip] Source reconstruction with MNE
>             problem: vol doen's fit        sourcespace
> 
>              >
>              > >
>              > > Hello, i'm trying a source reconstruction of event
>             related fields using minimun-norm estimates and i get a
>             problem with vol and sourcespace. When plot them together
>             the vol doesn't fit the sourcespace. I adjunted in the mail
>             two images where you can see what i get. It looks like that
>             there isn't any problem of coordinate system also the units
>             seem to be ok. I also procesed all the file with freesurfer
>             so i suppose there is no problem with the orig-nomask.mgz.
> 
>              >
>             Hope anyone can help me. Thank you very much.
> 
>              > >
>             Ion
> 
>              >
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> 
> 
>          >
> 
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Language and Cognition Group
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Neurobiology of Language Group

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