Begin forwarded message:

From: Garikoitz Lerma Usabiaga <garikoitz@gmail.com>
To: Louis Nicholas Vinke <vinke@nmr.mgh.harvard.edu>
Subject: Re: [Freesurfer] Register ROI5.nii to fsaverage in tutorial "Cortical Thickness of a Volume-defined ROI"?

Thanks for your answer Louis,

I think I'm using it, the steps were:
1- Correct visualization of ROI with:  tkmedit -f TT_avg152T1.nii -overlay ROI45.nii -fthresh 0.5

2- I execute spmregister: spmregister --s fsaverage --mov ../../ROI2/TT_avg152T1.nii --reg TT_avg152T1_to_fsaverage.dat


3.-Incorrect visualization when I execute: tkmedit fsaverage T1.mgz -overlay ../../ROI2/ROI45.nii -overlay-reg TT_avg152T1_to_fsaverage.dat -fthresh 0.5 -surface lh.white -aux-surface rh.white

What I understand is that the .dat is a transformation matrix between TT_avg152T1 and fsaverage, so when I am asking to overlay ROI45.nii, I am asking tkmedit to transform it to fsaverage by the .dat file. Is that correct? What do you think that could be the error? I am attaching the images just in case...

Thanks again,
Gari

PS This is the TT_avg152T1_to_fsaverage.dat:
fsaverage
2.000000
2.000000
0.150000
1.000000000000000e+00 0.000000000000000e+00 0.000000000000000e+00 0.000000000000000e+00
0.000000000000000e+00 0.000000000000000e+00 1.000000000000000e+00 0.000000000000000e+00
0.000000000000000e+00 -1.000000000000000e+00 0.000000000000000e+00 0.000000000000000e+00
0 0 0 1
round


















On 2012-07-12, at 17:56, Louis Nicholas Vinke wrote:

Hi Gari,
When you view the ROI5.nii on fsaverage make sure you include
'-overlay-reg TT_avg152T1_to_fsaverage.dat'.  TT_avg152T1_to_fsaverage.dat is the transformation computed in the previous step which you need to apply.  Nothing was resampled in step 2.
-Louis

On Thu, 12 Jul 2012, Garikoitz Lerma Usabiaga wrote:

Dear All, I am trying to automate ROI creation in freesurfer following
the VolumeRoiCorticalThickness tutorial, based on the AAL defined ROI-s from MarsBar.
QUESTION
ROI5.nii was originally in the same space as TT_avg152T1.nii (see MORE INFO below).
I understand that after Step 2  (when  TT_avg152T1.nii is registered to fsaverage with
spmregister), TT_avg152T1 will be in fsaverage space.
But, we didn't transform or register ROI5.nii, so I understand that it will continue in the same
original space.
When I visualize ROI5 over the original TT_avg152T1 it is ok, but when I visualize it over the
fsaveraged one, it is not.
Shouldn't we need to register or normalize ROI5.nii to fsaverage as well prior to the
mri_vol2surface mapping?
MORE INFO:
1.- I created the ROI5.nii in MarsBar: "ROI definition" > "Export" > "Export ROI to image"
(select: MNI_Frontal_Inf_Tri_L_roi.mat) > from image (select: avg152T1.nii) > Save it (name:
ROI45.nii)
2.- I follow exactly the same steps as the tutorial, but in step 3) when I check the ROI in the
inflated surface, it is clearly out of place...
Thank you very much in advance,
Gari
Garikoitz Lerma Usabiaga
Predoctoral Researcher
www.bcbl.eu



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