Dear Ben,
Thank you very much for the information. I am sorry for replying you late as I had to think about this matter for a while. I thought, DARTEL templates are normalized into MNI space.
So probably the reviewer's critical point might be that DARTEL templates are so refined and they wouldn't be congruent with the old atlases in the MNI space (which may not be so refined in terms of sulcus etc and which can't take advantage of the DARTEL's refined templates) or something.
However, I am not still sure and will see how the atlases are made in the WFU_Pickatlas and they go well with the DARTEL templates. And I will take your information into consideration.
Best regards,
Takeuchi
-----Original Message-----
From: SPM (Statistical Parametric Mapping) [mailto:[log in to unmask]] On Behalf Of Benjamin Wagner
Sent: Thursday, April 10, 2014 2:55 AM
To: [log in to unmask]
Subject: Re: [SPM] Questions related to DARTEL procedures and ROI definition in DARTEL space
Dear Takeuchi,
The reviewer is incorrect. The PickAtlas ROIs use existing label atlases including the AAL atlas and the TD atlas resampled to MNI space. These ROIs get resampled to the space of the SPM being displayed. There is no PickAtlas single subject structural brain MRI.
Best regards,
Ben
-----Original Message-----
From: SPM (Statistical Parametric Mapping) [mailto:[log in to unmask]] On Behalf Of Hikaru Takeuchi
Sent: Wednesday, April 09, 2014 8:29 AM
To: [log in to unmask]
Subject: [SPM] Questions related to DARTEL procedures and ROI definition in DARTEL space
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
|