Hi all, I have 3 Proton Density masks that were created on different computers using FSLview and for some reason I cannot merge these masks together. Although the orientations look correct within FSLview and I am able overlay all masks on top of one another, when I try to merge the masks together, I get the following warning: <<<Inconsistent orientations for individual images when attempting to merge.>>> fslhd info shows different q and sform orientations between masks mask 1 and 2: qform_xorient Right-to-Left qform_yorient Inferior-to-Superior qform_zorient Anterior-to-Posterior sform_name Scanner Anat sform_code 1 sto_xyz:1 -0.374352 0.021748 -0.004721 91.568634 sto_xyz:2 0.006226 0.046610 -0.496053 19.196569 sto_xyz:3 0.021137 0.371456 0.062521 -99.225533 sto_xyz:4 0.000000 0.000000 0.000000 1.000000 sform_xorient Right-to-Left sform_yorient Inferior-to-Superior sform_zorient Anterior-to-Posterior Mask2: qform_xorient Right-to-Left qform_yorient Posterior-to-Anterior qform_zorient Inferior-to-Superior sform_name Aligned Anat sform_code 2 sto_xyz:1 -0.375000 0.000000 0.000000 96.375000 sto_xyz:2 0.000000 0.375000 0.000000 -90.375000 sto_xyz:3 0.000000 0.000000 0.500000 -32.000000 sto_xyz:4 0.000000 0.000000 0.000000 1.000000 sform_xorient Right-to-Left sform_yorient Posterior-to-Anterior sform_zorient Inferior-to-Superior When I use fslswapdim to change orientations between planes (e.g. fslswapdim <infile> RP IS AP <outfile>) the mask is totally flipped around in orientation when I open it using FSLview and it cannot be overlaid on top of the other masks. Does anyone know how to approach this problem? Thanks! Krista