Hi Bronwyn,
with FS 5.3 you can run the single-tp images through a 'fake' longitudinal stream. After processing crossectionally simply run the base with only the single time point, and then run the long with that base. This will make the results comparable as the images will go through same processing steps.
If it makes sense to include them into your model depends on what you are testing and how many there are. In linear mixed effects models, having a extra few single time point values helps for the estimation of cross subject variance.
Best, Martin
On 01/18/2016 05:09 PM, Bronwyn Overs wrote:
Hi Freesurfer Mailing List,
We are running a longitudinal analysis (in R) using 2 time points with scans that have been through the Freesurfer longitudinal pipeline. We were also hoping to incorporate individuals with only a single scan into our analysis. Does it make sense to use long images (2 timepoints) with cross images (1 timepoint) in the same analysis, or can they not be used together because the cross sectional images have not undergone the same processing steps? --
Kind regards,
Bronwyn Overs Research Assistant
Neuroscience Research Australia
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