Thanks John,
I am assuming it would be incorrect to create a template from all timepoints (as we expect differences between trx arms).
Just to clarify, you are saying I should create flow fields from just timepoint 1, and then sequentially apply these flow fields to each timepoint for both GM and WM segments? E.g. u_rc1 from timepoint 1 applied to a GM segment in timepoint 2
Is it incorrect to segment al ldata normally using "new segment" then creating flow fields and normalizing, instead of just segmenting timepoint 1?
Thanks
AK
-----Original Message-----
From: John Ashburner [mailto:[log in to unmask]]
Sent: Wednesday, January 11, 2012 1:34 PM
To: Kairys, Anson
Cc: [log in to unmask]
Subject: Re: [SPM] DARTEL template from baseline scan, applied to other timepoints
Yes. That should be possible.
1) First of all, make sure that all your data are coregistered within subject.
2) Then do the segmenting and Dartel estimation on the first time point data.
3) Write spatially normalised versions of the first time point data using the estimated deformations.
4) Write spatially normalised versions of the second time point data using the estimated deformations.
etc
One thing to be careful of are systematic biases resulting from treating the first time point data differently from the others. See the recent commentaries in NeuroImage Volume 57, Issue 1 to see if these relate to your plans for the data.
Best regards,
John
On 11 January 2012 18:21, Anson Kairys <[log in to unmask]> wrote:
> Hi DARTEL users,
>
> I am trying to compare timepoints of drug trx (e.g. pre vs post treatment). I want to make the DARTEL template from their baseline scans, then use this template for normalization with the other timepoints. Is this possible without creating flow fields for all timepoints?
>
> thanks
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