yes, it's definitely not recommended. On Tue, 20 Oct 2009, Narly A Golestani wrote:

Hello all,

I would like to know whether the T1 parameters such as TR, TE, TI, and flip angle can systematically influence mean curvature values obtained by recon-all -all.

I have processed 2 data sets with the following T1 parameters, and am noticing that the mean curvature values systematically bigger in the former compared to the latter data set in 78% of the brain regions segmented in the default (Desikan) atlas.

data set 1: TR=12.24, TE=3.56, TI=530.00, flip angle=23.00 Original Data has (1, 1, 1) mm size and (240, 256, 176) voxels

data set 2: TR=20.66, TE=8.42, TI=640.00, flip angle=25.00 Original Data has (1, 1, 1) mm size and (224, 256, 176) voxels

More generally, I would like to confirm that it's not recommended to combine data based on different scanning parameters in one study, due to possible systematic differences in the segmentation output related to scanning parameters.

thanks in advance and all the best, Narly.

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