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#7 voxel dimensions_ROI extraction in Marsbar

v1.0 (example)
open
nobody
None
5
2022-02-02
2022-02-02
Narges
No

Hello,

I have a question about voxel dimensions when extracting grey matter ROI intensities using Marsbar. I followed two different procedures:

First procedure: I used get spm cluster function and then extracted ROI data (full option) from the mwrp1 images (1.5x1.5x1.5 voxel dimensions) .

Second procedure: I created ROIs using the aal3 atlas for marsbar. These ROIs were then resliced in SPM12 to match the same dimensions of my sample-specific DARTEL (1.5x1.5x1.5). To extract data, I converted the resliced ROIs into mat files and then extracted ROIs using the same method as above.

My problem: when I view the mat files in Marsbar, the voxel dimensions are in 2x2x2, whereas my mwrp1 images are in 1.5x1.5x1.5 dimension. It seems to me that spm clusters are saved in 2x2x2 by default (in procedure one), and conversion of nii image to mat file changes the voxel dimensions to 2x2x2 (procedure two).

I assume that this would affect the ROI intensities (Y values) that I will get after extracting and saving data as mat files? Is there any thing I could do to fix this problem?

Thanks in advance for your help,

Narges

Discussion

  • Matthew Brett

    Matthew Brett - 2022-02-02

    I'm sorry - I'm hardly using this forum - would you mind posting over at https://marsbar.discourse.group/ ?

     

  • Narges

    Narges - 2022-02-02

    Hi Matthew,

    Thanks for letting me know! I've just posted my question to the https://marsbar.discourse.group/.

    Regards,

    Narges

     

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