Hi, Ellen-

The "-obliquity" scalar value output by 3dinfo tells what the largest angle of rotation there is between your FOV coordinates and the scanner coordinates (the obliquity with which the data was acquired); the most important thing here is that your input dsets for a particular subject have differing obliquity. You also having difference matrix sizes for dsets for a given subject (for your Subject A, "128 135 81" is your matrix size for a couple data sets and " 128 128 66" is the matrix size of other ones). It will be impossible to combine these datasets that on different grids (and possibly not even overlapping, in reality).

I'm a little perplexed about how this occurs for only some and not all subjects. Do you have one processing script that you have used, going back to converting DICOMs?

--pt