open-discussion > Voxel values?
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Sep 15, 2011  09:09 PM | Jesse Brown
Voxel values?
I've got a couple points of confusion regarding the intensity values at each voxel in the .nii parcellation files (eg tcorr05_2level_all.nii.gz).

1) What are the values at each voxel? I expected they'd be integer values labeling each of the 190 ROIs but they have fractional values instead.
2) Why aren't the values for neighboring voxels the same? I expected that because these ROIs are supposed to be spatially contiguous, neighboring voxels that belong to the same ROI should have identical numerical values/labels.

I'm trying to figure out the best way to threshold ROIs one by one. If I missed some documentation that explains this, feel free to just point me to that. Otherwise, looking forward to your reply. Thanks for sharing these!

Jesse
Sep 22, 2011  12:09 AM | Cameron Craddock
RE: Voxel values?
Hello Jesse,

I am very sorry for my late reply. I figured out the problem. In my haste to get the images uploaded I made an error in my script to concatenate all of the parcellation atlases into a single file. This has been corrected and I have uploaded the fix. I have also added documentation for the atlases on the wiki.

I really appreciate you pointing out this issue.

Regards,
Cameron