Hello,
I need some help understanding the meaning of PET Population Main effect:2
conditions, 1scan/cond (paired t-test) model results:
I have 10 patients with 2 PET (simple inject,wait and scan type) scans each
(act and baseline)=20 scans. I want to analyse the subtraction images.
I coregistered each pair of images, estimated spatial normalisation parameters
from one and then applied the same warps to both, then smoothed (12mm), and
used the above mentioned model to do the paired t-test because I want to find
out whether there is any difference between act and baseline scans. I also
used proportional scaling.
In the model I included all 10 subjects, specified 2 scans per subject, and
simply entered 1 2 in for the required condition vectors in the model.
When I clik on Volume in the Results, I get quite a few sign. vol.printed
out... and when I render the results, the brain template becomes completely
red - I guess this means there is a difference between the scans...
I am not sure how to interpret this? Do these results apply to the group as a
whole? How could I look if there what kind of difference on pt by pt basis?
What model would I have to use if I wanted to add pts' Depression score into
the model - a nuisance var? I also don't understand how nuisance var can be
entered as vectors...
Any help would be much appreciated.
Mateja de Leonni
|