Hello SPMers,
I'm being uncertain on the analysis i'm doing these days, so i share it with
you.
We have imaged 3 groups (unipolar depressed (UNI-D), bipolar depressed
(BIP-D) and a control group (CON) ) with SPECT perfusion imaging.
We would like to see if there is a difference between the UNI-D and the
BIP-D perfusion, in contrast with the CON perfusion.
Our idea is to do a multiple regression analysis, with four columns + mean :
UNI-D CON BIP-D CON mean
1 0 0 0 UNI-D group
0 1 0 0 CON group
0 0 1 0 BIP-D group
0 0 0 1 CON group
Then, we used a +1 -1 -1 +1 ((+1 -1) - (+1 -1)) contrast to test an
hyperperfusion (hyper related to control) in UNI-D compared to
hyperperfusion in BIP-D.
Pb : using this contrast, we also test an hypoperfusion in BIP-D conpared to
hypoperfusion in UNI-D.
How could I redo this analysis in order to be able to test these two
hypothesis separately ?
An initial idea was to do a first-level test (UNI-D vs CON and BIP-D vs CON)
and then use the con images (2 images). But i'm uncertain on which test to
do with this two images. Is that a good strategy ?
Thanks in advance for your help,
Christopher Coello,
Postdoctoral Research Fellow
Center for Diagnostic Imaging,
Akershus University Hospital,
Sykehusveien 25, 1478 Lørenskøg
tel : +4745154516
e-mail : [log in to unmask]
|