I am using Freesurfer version 7.3.2 on a mac. 

I am using the mri_label2vol function to project an anatomical label into volume space, but I realised the label comes out wrong when I use the --fill-ribbon flag: its orientation changes to RSP. 

The same label comes out right when I use the --fillthresh flag (oriented in RPI). 

Any idea why using --fillribbon changes the orientation?

Thank you in advance.

Best wishes,
Letitia