If existing processing files exist before import is run, they should not be ignored but copied to /derivatives/ExploreASL (if they were in the root folder), then appended with missing fields.

• dataPar.json (will be renamed later to ExploreASLPar.json)
• dataset_description.json
• participants.tsv

Some merging is done already (participants.tsv e.g.). Re-use merging functionalities?

Release notes

Nothing.