Once you have data for a cohort in your local XNAT instance that can be pushed to the hub, you’ll need to create a data freeze. During the lifetime of a research project you might have several data freezes associated with a project. The first cohort might consist of control subjects that is followed by a data freeze of all subjects sometime after the study has been closed and written up. On the hub you will have control over what data freezes are searchable. It is also possible to construct a cohort on the hub with data freezes from multiple institutions, to accommodate multi-centre imaging trials. If you do use multiple data freezes to push data to the central hub you must ensure that subjects are not duplicated across freezes. Duplicating subjects in freezes will be reflected in incorrect hub counts and duplicate data in downstream porjects.
Data freeze process
There is a three step process to publish a data freeze on the hub.
- Step 1 – Create data freeze
- Step 2 – Push data freeze to the hub
- Step 3 – Enable the freeze on the hub