Hi Tommaso -

Thanks for the headers. Unfortunately, I cannot reproduce your problem. When I read volumes with the two different pixel sizes, they both show up correctly, and I get no NaNs clicking on pixels either.

Here's another thing to try - could you run the following command on each of the two volumes and post the resulting output here:

describe --read-ras VOLUME.nrrd

where "VOLUME" is whatever file name your volume uses.

This tool internally uses the exact same library functions to read and reorient the image data, so perhaps that will shed some more light on what's going on.

Now, one other thing - while I have never seen  or heard of the problem you described, can you just confirm that you are using the latest version of CMTK?

Best,
  Torsten