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Most experiment data in XNAT is associated directly with a subject. In turn, a subject can have multiple experiments. Subject information can be as brief and simple as an identifier. Or, it can contain in-depth demographic information. Either way, creating a subject is required to add imaging data (as well as subject assessment data).
There are multiple ways to store subjects in XNAT:
Within the website there are two interfaces for creating subjects; Create Subject Page and Image Archive page. The most common mechanism for adding subjects is the Create Subject page which can be accessed through New -> Subject. This same interface is used for creating new subjects or editing existing ones.
The standard XNAT structure allows for each subject to have an identifying string for each project it is a part of. When adding (or editing) the subject you will supply this project-based ID. Behind the scenes every subject will be given a unique ID by XNAT (based on the project it belongs to).
Next, the create/edit form contains entry boxes for all of the variables which have been selected for this subject. This will include the default demographic fields (DOB, Gender, etc), as well as any custom variables you defined through the Custom Variables interface.
As a quick entry point, XNAT allows users to insert the subjects with the image archiving sequence. An interface similar to the one above is included in the archiving page.
Users also have the option of creating an xml document for each subject in their project, and directly storing that document into the application. This can be done through the web interface (Upload XML) or through a command line tool (which uses web services to store the xml). This is especially helpful for users who are converting from another xml structure, or generating subjects in another programmatic way.
The most common way to upload large numbers of subjects is the Upload Spreadsheet feature. This feature allows users to create spreadsheets contain information about each subject (based on a generated template). The subject can then upload that spreadsheet through the web interface. This process allows users to get large projects into XNAT quickly.
Advanced users may want to bypass the UI and use the XNAT REST API to create subjects: Create Subjects with XNAT REST API
Once subjects have been uploaded using one of the mechanisms above, the details about those subjects is easy to review. First, the user can quickly see a summary of information through the subject listing on the Project Report. Then, by clicking on individual subjects, users can review in-depth information about the subject on the subject report.
The subject report can be used to navigate a subject’s experiments, add new experiments, and retrieve XML documents. It displays all of the information defined in the project’s variable sets for the subject datatype.