Thanks for your reply @franklin. As I understood the paragraph regarding the *facemask.nii files, they are for storing the binary mask, not the anonymized MRI, but maybe I misunderstood it. It says:
If the structural images included in the dataset were defaced (to protect identity of participants) one CAN provide the binary mask that was used to remove facial features in the form of
_defacemask files. In such cases the OPTIONAL
mod-<label> key/value pair corresponds to modality label for eg: T1w, inplaneT1, referenced by a defacemask image. E.g.,
If this is the case, maybe a solution could be to put the sub-01_T1w.nii (anonymized with deface) at the root level, and add the maskface image in an anat folder inside the derivatives > epochs folder (which is already in .bidsignore). And once the specification is extended to allow multiple anonymized images I can update the dataset.
Do you think it mught be a viable solution?
Cheers and thanks again for all your help!