The Extensible Neuroimaging Archive Toolkit

The Extensible Neuroimaging Archive Toolkit (XNAT) is a software
platform designed to facilitate common management and productivity
tasks for neuroimaging and associated data. In particular, XNAT
enables qualitycontrol procedures and provides secure access to and
storage of data. XNAT follows a three-tiered architecture that includes
a data archive, user interface, and middleware engine. The XNAT
framework relies heavily on XML and XML Schema for its data
representation, security system, and generation of user interface
content. XML provides a powerful tool for building extensible data
models. This extensibility is particularly important in rapidly
advancing fields like neuroimaging, where the managed data types are
likely to change and evolve quickly. XML Schema has become the
standard language for defining open and extensible XML data formats.
As a result, many biomedical organizations have developed or are
currently developing standards in XML. XNAT uses a hybrid storage
architecture that leverages the strengths of XML, relational
databases, and standard file systems. Data stored by XNAT are modeled
in XML using XML Schema. From the XSDs supplied by a site, XNAT
generates a corresponding relational database that actually stores
all of the nonimage data. XNAT automatically imports and exports
compliant XML to and from the generated database. Image data remain
as flat files in their native format (e.g., DICOM) on the file
system. These files are represented as URI links in the database
and XML. This hybrid XML/relational/file system architecture has
a number of advantages. By building on a data model in the XML domain,
the XNAT platform is able to generate a great deal of content from
the known structure of XML documents and XNAT sites can easily
utilize the growing set of XML-based services and technologies. By
storing the text and numeric data in a relational database, the
typical drawbacks of XML data representations -- inefficient storage
and querying -- are avoided. By storing the image data in flat files,
the cumbersome nature of binary types in XML and databases is avoided
and the images can be directly accessed by users and applications. CLICK HERE See also the XNAT project web site: More Info