Dear all,

I have a quick question regarding the appropriate design (DOSS, DODS, SOSS, SODS) to be used with QDEC when comparing LGI values for 2 groups (patients and healthy controls). I have noted that a number of publications have used DODS when comparing LGI values between 2 groups while controlling for age and gender, but I was just wondering if this is the correct design to use for this type of analysis.

I am aware that only DODS and DOSS can be used with QDEC but that it may be possible to use SOSS or SODS with mri_glmfit. I would like to be 100% sure about which is the most appropriate design to use. I have 2 groups with 29 subjects in each group (N = 58). The reason I ask this is because I am wondering whether it would be better to use SOSS (same offset same slope) when looking at LGI because, as I understand it, cortical folding patterns are roughly determined in the first few months of life and remain relatively stable into adulthood, unlike cortical thickness which is much more dynamic. If the results of this analysis are significant after FDR correction I would assume that this suggests that cortical folding patterns are indeed different in the 2 groups.

Any help or advice on this would be greatly appreciated.

Thank you so much in advance.

BW

Marco