Dear Dr. Gaser, Dear CAT12 experts,
For a study of patients with Alzheimer’s dementia we want to use a customized DARTEL Template.
To do so, I was following the CAT12 Manual, but have come to a bit of a conundrum. Could you kindly clarify what is the correct procedure?
So far I had performed these steps:
1) Segment data
2) Run DARTEL (create Template)
3) Normalize to MNI space (output: smwrp1*_affine.nii)
The next step, however, is marked with a word “optionally” (re-use of customized DARTEL Template on age-wise close data) and, thus, it is a bit unclear to me whether it has to be performed or not.
Searching in the SPM archives, I found following opinions:
>2016-08-11 MRI More <[log in to unmask]>:
>> "You really only have to repeat the segmentation module if you think that
>> the first affine registration is going to differ to a relevant part from an
>> affine registration onto the study-specific template."
>2016-08-10 Marko Wilke <[log in to unmask]>:
>> Hence, my question is whether the images coming out of step 3
>> (smwrp1*_affine.nii) are the images already registered to the customized
>>No, otherwise the 4th step would not be necessary. You need to do two rounds: >> one, to segment your data based on a standard template, then use the affine->> registered images to create your own DARTEL template, then repeat the
>> segmentation with your own template.
Thus, could you please clarify whether the “smwrp1*_affine.nii” images of the first segmentation round are affine-registered to DARTEL? If so, is it still advisable to repeat the segmentation? What is the benefit of this procedure and in which case it might be helpful?
I would be very grateful for any input on my question.
M.S. in Interdisciplinary Neuroscience, Dipl. in Clinical Psychology
Marie-Curie Early Stage Researcher under ITN-ETN H2020 BBDiag project
Dept. Physiology and Pharmacology
Sapienza University of Rome