Hi
I have two groups I want to compare, in total 172 scans Of these 78 got a a follow up. Groups are approximately evenly distributed.
I want to do first a cross sectional comparison and subsequently a longitudinal analysis for the 78 subjects only.
My question is: (1) Is it is valid to analyse all data using the longitudinal processing stream ( e.g. recon-all -all, recon-all -base, recon-all -long), even though I do separate cross sectional and longitudinal analyses? Or (2) should I analyse first the 175 using the cross sectional stream and then separately analyse the 78 with a follow up scan with the longitudinal stream?
Of course I would prefer option 1 as that would reduce potential editing/adjusting
many thanks in advance William
Hi William,
either way is fine, as long as you don't mix results from cross and long processing in your analysis. Since all images need to go through the cross sectional stream anyway, I think actually (2) will be less processing (and potentially less QC and editing).
Best, Martin
On 06/10/2016 09:12 AM, William Baare wrote:
Hi
I have two groups I want to compare, in total 172 scans Of these 78 got a a follow up. Groups are approximately evenly distributed.
I want to do first a cross sectional comparison and subsequently a longitudinal analysis for the 78 subjects only.
My question is: (1) Is it is valid to analyse all data using the longitudinal processing stream ( e.g. recon-all -all, recon-all -base, recon-all -long), even though I do separate cross sectional and longitudinal analyses? Or (2) should I analyse first the 175 using the cross sectional stream and then separately analyse the 78 with a follow up scan with the longitudinal stream?
Of course I would prefer option 1 as that would reduce potential editing/adjusting
many thanks in advance William
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William Baare