Dear SPM mailing list,
I am undertaking a VBM study where data was collected on two different scanners. The data set has clinical and control groups, with data from the same number of participants from each of the two groups collected in each of the scanners. When I run my grey matter group contrast analyses, is it correct to run as a two sample t-test, with the scanner entered as a covariate (scanner 1 entered as 0s and scanner 2 entered as 1s)?
I have checked that there are no differences in the group contrasts by running a full factorial design with two factors: 1) Group (2 levels), and 2) Scanner model (2 levels), and there are no significant clusters for the interaction between group and scanner.
Thank you in advance for assistance.
Jess.
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