new feature

[CPernet]

See rordenlab/dcm2niix#802, if adding some dcm2niix tag we can add metadata
@MarDos1234 we would need to see with you how this would work

[bendhouseart]

@bendhouseart need to test changes here with the development version of dcm2niix and follow up with @MarDos1234 after adding in the ability to export weight from pet2bids.

[bendhouseart]

Additional tags added in -> d17927e17f436b2942a20e787150abe55f1b334f on dcm2niix dev branch?