Creating and Managing Projects

Data stored within XNAT is organized according to projects. To manage data within your XNAT you will need to create projects which your data can be assigned to. In some situations, these projects correspond directly to grant approved studies. In other situations, projects can correspond to individual collection sites for a multi-site study. You are free to use any project organization scheme you choose. However, remember that user permissions for access to data are governed by the user's access to particular projects. So, if you only have one project in your XNAT, you will have limited options for governing access to that data.

All data stored in XNAT must be associated with a project. This association is the basis of the XNAT security model. Users are given access to data which belongs to a particular project. In order to upload any data to XNAT, you must first create a project.

1. Creating a Project

Go to New -> Project in the top menu bar.

Populate the project fields.
  • Title: the full title of your project.
  • Running Title: A brief description of your project (a few words which will appear throughout the website).
  • Project Abbreviation: One word or acronym to refer to your project. (The value of this will be used to name files on the file system.)
  • Description: A detailed description of your project
  • Keywords: A few keywords which describe your project.
  • Alias: Keywords by which this project could be referred to.
  • Investigators: The people who will be investigators for the project. They do not need to be XNAT users and can be added dynamically.
Select the default accessibility of your project.
  • Private: Only you and users you select will be able to access study data.
  • Protected: All users will be able to see your study title and description, but only users you approve will be able to analyze and download data.
  • Public: All users will be able to access study data for analysis and download.

After completing the project creation dialog, you will be taken to the Project report page. This page is the central place for dealing with your new project. From here you can manage user access, manage project protocol details, monitor project progress, and directly manage stored data. Take some time to familiarize yourself with the options the Project Report page offers. They are different depending on your role in the project (Project Owners can manage user access, Project Members can create and edit data, Project Collaborators can only read/download data).

2. Managing User Access

You have several options for how your project is accessed by other users. You can tighten security to the point where no one will know your project exists. Or you can loosen it to allow anyone to access it.

All of the project access options are managed from the Access Tab on the Project Report.

Naturally, only individuals with valid user accounts can access data stored in an XNAT instance. For individuals who have user accounts, you have two methods for controlling access to your project; default accessibility and specific user roles.

Defining the Default or Public accessibility determines the access which average users have to your project.  Private accessibility prevents any user (other than ones you specify) from seeing your project or knowing that it exists.  Protected access will prevent users from accessing the data stored within your project, but they will still be able to see the project summary you defined. They will be allowed to request access to your project data via an automated process.  Public access will allow all users to access your project and its data without your involvement (but not create or edit that data).

Related: User Roles and Permissions.

Data Ownership

Subjects and experiments are always owned by one (and only one) project. This project governs the ability of users to modify the data. When data from one project is used by a different project, this is called ‘sharing’. Subjects and experiments can be shared into different projects. 

A user must be a member or owner of the Owner project of an item in order to edit that item. Shared data is not editable by members of the new project (unless they are also members of the first project).

3. Adding Custom Variables

XNAT is built on a core XML Schema model which represents the common structure of neuro-imaging data; Projects, Subjects, Imaging sessions, Subject Assessments, etc. XNAT was built to support the lowest common denominator of data points in each level of this structure. In some situations, this model may be sufficient for your needs. When it is not, you can add your own customizations to the model by extending the XML Schema model with your own schema. However, when your customizations are limited to a few variables, XNAT provides an interface for dynamically adding these variables through the web interface (bypassing the need to create a custom XML Schema).
To create custom variables, click the Manage Custom Variables link on the Project report. This will bring up the Custom Variable management interface.

You have the ability to add variables to the subject, or any of the experiments you selected as part of your project. Select the appropriate data type from the drop down list. This will display the predefined variable sets. Some of these sets were created by XNAT at installation, others may have been added by other users. First, review these predefined variable sets to see if your variables have already been created. If not, click the Add a Custom Variable Set. This will bring up the form for adding your custom variables. Each variable must be contained within a variable set. First, define a name for your set (used in the forms and report to group your variables) and a description. Then add one or more variables. When you have finished making your desired changes, click the Save button at the bottom of the screen. ATTENTION: Your changes will be lost if you don’t save them.


4. Monitoring Project progress (Searching & Stored Searches)

The progress of your project can be monitored from the Project Report. The report includes two important sections for monitoring progress: Details & Listings.
The Listings section displays detailed information about the data you have stored in your project.

The Project Listings section is a central point for XNAT users. From it you can quickly view the data within a project and link to particular entries. The listings are loaded page by page (page size is customizable by changing the number in the dropdown above the table.).

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