MIRC Overview - CTP and TFS

1 About the MIRC Project

The MIRC project was initiated by the RSNA Radiology Informatics Committee to construct a library of medical information, globally accessible to the imaging community through the Internet. The project has evolved to support communities of cooperating libraries, individually managed by healthcare and educational institutions, whose content can be accessed by a user as if it were a single library. The libraries can provide all kinds of digital information, including teaching files, clinical and technical documents, electronic presentations, and imaging datasets for research and clinical trials.

The RSNA manages an open-source project that has produced software making it easy to install a system for teaching files and clinical trials at no cost. Numerous other developers have produced complete or partial MIRC implementations.

2 The MIRC Community

Many MIRC communities have arisen - some within institutions and some shared globally. The RSNA maintains a MIRC site that provides access to libraries around the world.

Any MIRC site can function as an access point for users, called a query service, or an indexed information library, called a storage service, or both. A query service provides a point of access to a MIRC community. It provides a query form to the user, distributes the search criteria to all selected storage services, collates the responses, and presents them to the user. A storage service responds to the query received from the query service, searches its index for documents meeting the search criteria, and returns abstracts and locations of the matching documents to the query service.

Authors on a storage service can use a MIRC-defined format to construct teaching files and other documents in a common structure that allows libraries to index the documents in medically meaningful ways. The indexing mechanism provides users great flexibility in searching the MIRC community. Users can perform free-text searches on the contents of documents as well as structured searches on patient criteria (e.g., sex, age), image criteria (e.g., modality, anatomical region, storage format, compression), diagnosis and other codes, through a standard web browser.

There are several ways for an individual or an institution to establish a system that can participate in a MIRC community:

• The RSNA MIRC software provides both a query service and a storage service as well as support for the MIRC-defined authoring format.
• An existing teaching file system can be modified to use its internal database to provide an index of its documents, requiring only the construction of the software layer necessary to respond to a MIRC query.
• Some commercial teaching file systems also support the MIRC query mechanism, allowing them to participate in a MIRC community.

3 User's Manual

The RSNA MIRC implementation has numerous components for accessing, creating, and managing documents and files. Information on how to use the RSNA MIRC software is collected in a separate article.

4 Administrator's Manual

The RSNA MIRC implementation is designed to minimize management effort. The MIRC Administrator's Manual describes how to set up a MIRC site using the software and how to configure it to meet the needs of its users.

5 Clinical Trial Administrator's Manual

The RSNA MIRC implementation includes a powerful suite of tools to support both single-site and multi-site clinical trials. A separate article, intended for clinical trial administrators, provides details on configuring the software for a trial. Some of the information may also be useful for MIRC site administrators who want to enable DICOM communication with PACS or modalities and who need to configure the system to manage PHI in accordance with HIPAA regulations.

6 Developer's Manual

The RSNA MIRC implementation is an open source project. Developers are welcome to download the software, modify it for their own purposes, and to participate in the extension of the software for the entire community.

There are several separate articles which may be of use in this context:

• The RSNA MIRC Source Code describes the RSNA CVS repository and how to obtain the code from it. It also describes how to build the software using Ant.
• Implementing an External Database Interface for MIRC Clinical Trials describes how to interface an external database to the Database Export Service on a storage service used for a clinical trial.

All MIRC XML files are described by schema documents:

• The MIRCdocument Schema describes all the elements in a MIRCdocument.
• The MIRCquery Schema describes the XML object that carries a query from a query service to a storage service.
• The MIRCqueryresult Schema describes the XML object that carries query results from a storage service back to a query service.
• The MIRC Protocol for Document Exchange describes the packaging of a MIRCdocument for exporting from one MIRC site or importing into another one.
• The Storage Service List Schema describes the XML object for exchanging lists of storage services among query services.

8 Tools

The RSNA MIRC project has developed several tools which are not part of the MIRC site software but which are useful as stand-alone applications in MIRC-related projects. The source code for all the tools is part of the RSNA MIRC Source Code. The key tools are:

• DicomEditor: a tool for examining DICOM objects and for testing anonymization scripts for clinical trials. This tool is also useful for correcting certain problems in DICOM objects.
• FileSender: a tool for transmitting files of various types using the DICOM, HTTP, and HTTPS protocols. This tool includes a zip unpacking feature that is very useful when managing large groups of images in multi-centeer clinical trials.
• HttpTest: a tool for testing HTTP connections. This tool is useful for testing the connection of a remote image acquisition site to a principal investigator site in a clinical trial, especially when the remote site is behind a proxy server.
• DicomRouter: a general tool for routing DICOM transmissions to one or more destinations depending on their contents.
• ExportManager: an implementation of the IHE TCE integration profile, providing a very powerful coupling between PACS diagnostic workstations and MIRC.
• PowerpointTool: a Powerpoint plug-in that saves presentations as MIRCdocuments on a MIRC server.