Dear users of SPM8's VBM,
I used DARTEL procedures in a VBM study and used WFU_Pickatlas in this study to get the value of regional gray matter density of ROI in the VBM study.
I have a few questions related to VBM in SPM8, automatic anatomical ROI definition when DARTEL is used.
When this paper was reviewed, the reviewer gave us the following comment.
"The Pickatlas VOIs are based on the MNI single subject template and should hence most likely not be valid in the DARTEL template space ".
It seems to me if this is the case, all the existing procedures to use the anatomical atlas become invalid in studies using DARTEL.
But is this comment true (or practically valid enough)? And if so, are there any good methods to define roi automatically and anatomically in the DARTEL template space? For us, probably it is difficult to write ROIs (at least all of them) manually from the DARTEL template.
Second, in SPM8's new segmentation and DARTEL procedures, the VBM manual developed by Prof. John Ashburner (http://www.fil.ion.ucl.ac.uk/~john/misc/VBMclass10.pdf), tells to use rc1 and rc2 images for DARTEL procedures (and not rc3, rc4, rc5, rc6). Why are only these 2 image? We are using rc1, rc2, rc3, rc4 and rc5 (since rc6 image is the mainly all the space outside the brain) but the reviewer is seemingly questioning the methods that don't use all of 6 imported images. Are there particular reasons to use 2, 5 or 6 dartel imported images in DARTEL procedures?
Thanks in advance for help.
Best regards,
Takeuchi
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