Creating a Data Freeze

(part 1 of Data freezes)

The project actions menu of a DPUK XNAT instance has an additional Create Data Freeze action which you can use to prepare data for uploading to the DPUK Central XNAT instance.  When you click this action you will be taken to the first page of the data freeze menu.

The first page of the create data freeze wizard
The first page of the create data freeze wizard

The first page will partition the project subjects by research group, if defined.  In the above screenshot, no research groups were defined so only one group is shown.  It is typical, however, to label subjects as “controls” and “non-control” and if this was the case then you’d see two groups here. Furthermore, if any of your subjects were missing a research group attribute then they will be added to a third group.

The second page of the create data freeze wizard
The second page of the create data freeze wizard

A second attribute used in XNAT is visit label.  If for instance you had a “baseline” and “follow-up” visit in your study protocol and this had been added to your subject data then you would see two partitions to choose from here.

Page three of the create data-freeze wizard
Page three of the create data-freeze wizard

The third page of the wizard allows you to filter the data that will be included in the data-freeze and map scan types to the defined DPUK scan types.  Once you have selected the data you wish to include and click Next, you’ll be able to review a summary of you selections.

Page four of the create data-freeze wizard
Page four of the create data-freeze wizard

When you click the Save button you will be asked to supply a name, short name and description – a data-freeze is a special type of XNAT project.  It is recommonded that you include the term “freeze” or “data-freeze” prominently in your choices.

Naming the data-freeze
Naming the data-freeze

After you’ve saved the data-freeze you’ll see a modal progress bar and then be taken  to the project page of the new freeze.   Data will be copied from the original project to the freeze project.  While this is happening a “Preparing Data” banner will be shown on the freeze project page.

Screenshot from 2016-02-12 16-18-00
A banner will indicate when the freeze copying of data is taking place.

When you’re freeze has finished being prepared you can push the data-freeze to the hub.