BIDS validator rejects space entity in derived data

Hi there.

I’ve been trying to convert a dataset into BIDS for distribution, and we have a number of derived types from T1 MRI processing. My understanding of the BIDS validator is that it does not automatically look within derivatives/ and these datasets should be separately validated. However they are standard space registered and ideally I would use the space descriptor for them. BIDS Validator v1.11.0 does not believe this is valid if I point it within one of the derivatives datasets:

sub-188_ses-01_run-1_space-MNI305_T1w.nii.gz 4586.013 KB | application/gzip

Location:

ssp/sub-188/ses-01/anat/sub-188_ses-01_run-1_space-MNI305_T1w.nii.gz

Reason:

Files with such naming scheme are not part of BIDS specification. This error is most commonly caused by typos in file names that make them not BIDS compatible. Please consult the specification and make sure your files are named correctly. If this is not a file naming issue (for example when including files not yet covered by the BIDS specification) you should include a “.bidsignore” file in your dataset (see GitHub - bids-standard/bids-validator: Validator for the Brain Imaging Data Structure for details). Please note that derived (processed) data should be placed in /derivatives folder and source data (such as DICOMS or behavioural logs in proprietary formats) should be placed in the /sourcedata folder.

Evidence:

sub-188_ses-01_run-1_space-MNI305_T1w.nii.gz

But Common data types and metadata - Brain Imaging Data Structure v1.9.0-dev shows the space entity used for derivative T1w images (coincidentally with MNI305). Do I just ignore this error (not a warning)?

Could you exchange the place of space- and run- and see if you get better result?

The validator does not yet support derivatives. There is a deno-based validator that you can try and report issues for. See the validator GitHub repository for details.

See: bids-validator/bids-validator/src/README.md at master · bids-standard/bids-validator · GitHub