MIRC (Medical Imaging Resource Center) is an open source software project initiated by the RSNA Radiology Informatics Committee. Implementation of this software sets up a MIRC Web Server, usually on a computer within an institution that is connected to the intranet.
A MIRC Web Server
What is it for?
When implemented in an institution, a MIRC Web Server hosts one or more medical imaging libraries. These libraries contain MIRC Documents which can be searched, read, created, edited, and added to by users on the institutions intranet. MIRC Web Servers can be customized to suit the needs of the institution, and an individual users ability to find, read, create, and edit MIRC Documents is defined by user permissions determined by the MIRC Administrator.
What is a MIRC Document?
A MIRC document can be a radiology (or any other medical imaging) case, tutorial / exam style cases, powerpoint presentations, or clinical trial / research imaging datasets. Most MIRC documents contain images and text which are presented to the reader in a format chosen by the author. MIRC documents can also contain other files and references
How does a user find and read a MIRC Document?
The MIRC Website is accessed by the user via the intranet. It allows the user to search for MIRC Documents on one or more libraries based on different search criteria - much like searching on Google or pubmed. The user will be presented with a list of results (again much like Google or pubmed) each linking to a MIRC document. When searching the user can have the results presented as unknowns which hides the diagnosis until the end of the case. This is particularly useful for exam preparation.
How are MIRC Documents added to the MIRC Web Server?
- Users can be granted varying levels of access to the libraries allowing them to view, author, and edit documents. Via the MIRC website on the department intranet, a user can upload images and enter text fields to create a case.
- The MIRC web server can receive DICOM objects sent from any DICOM node (eg. a departmental PACS workstation). Depending on how the MIRC Web Server is set up - these images can reside in an online file cabinet for case creation at a later date, or they can be inserted into a blank MIRC Document to be edited at a later date.
- Extending the capability of receiving DICOM objects is the IHE TCE standards - many PACS vendors (Fujifilm Synapse and others) are implementing these standards, which will enable a radiologist (while reporting at a PACS workstation) to select relevant images from a case, enter relevant fields to create a teaching case (clinical history, findings, DDx for example) and send the case to the MIRC Web Server (as a MIRC Document) from their workstation. This is designed to make creation of teaching cases easy and fast for the radiologist, with minimal disruption to reporting work flow.
Who can access an institutions MIRC Web Server?
MIRC user accounts are set up by an administrator which allow varied levels of access to the MIRC Documents in the libraries hosted on the MIRC Web Server. A user may have permission to create, edit, and read documents in one library (the Wednesday Interesting Cases library for example), but only have permission to read (not edit or create) documents in another (the departmental teaching library for example).
Can the library be made available to other institutions?
At the institutions discretion, their libraries can be made available to other MIRC sites over the internet. One of the goals of the RSNA MIRC project is to facilitate the sharing of libraries around the world. Whether or not a department shares its library or not is entirely their prerogative. An institution's MIRC Web Server can be set up to search other shared libraries around the world.
Behind the Scenes
A MIRC web server is composed of a group of server-side applications (Java Servlets) hosted on an Apache Tomcat Web Server which interface with each other via structured XML and with the user (radiologist) via JSP web pages generated in run time and a client side web browser. The applets include the Query Service, one or more Storage Service(s), an Author Service for each Storage Service, a File Service, and an Admin Service. These applets communicate with each other via three different defined types of XML files known as MIRCquery, MIRCqueryresult, and MIRCdocument. The File Service exposes one or more DICOM SCU (Server Class Units) to which DICOM objects can be sent from a PACS, a modality workstation, or a reporting workstation.
The query service generates the front end HTML form presented to the user. The Storage Services available for the user to query is defined by the MIRC administrator, the user can select one or more of them from a list. The basic search function is a free text search (Google style), and the advanced options include various drop down boxes such as categories (MSK, neuro etc), difficulty levels for teaching cases, research database parameters (dates, anatomy, pathology, codes etc) for research / clinical trial databases. Based on input from the user, the query service sends a MIRCquery XML File to one or more Storage Services. The MIRCqueryresult XML File that is received in response is used to generate a webpage with a list of document titles, authors, and abstracts with hyperlinks to these documents. If the user specified "display as unknowns" on the front end web page, the alternative-title is displayed. eg "smoker with cough" rather than "lung cancer".
MIRCquery XML File
The MIRCquery XML file contains the search criteria from the user in a defined XML Schema. As noted in the query service section above this can be as general as a free text search eg "lung cancer", to a set of defined categories "level=primary, category=pulmonary...".
A storage service stores the MIRC documents. It receives an MIRCquery XML file, searches its database to find MIRC documents which match the criteria defined in the MIRCquery, and generates a MIRCqueryresult XML file which it sends back to the Query Service. When the URL of a MIRC document on a Storage Service is accessed the Storage Service renders an HTML webpage to present the document to the user. The manner in which the page is rendered is defined by elements in the MIRC Document as well as the administrator edited settings for the Storage Service.
MIRCqueryresult XML File
This file, generated by the Storage Service in response to a MIRCquery, basically contains a list of MIRC Documents, URLs for these documents, and various other features (author, abstract etc). It is sent from the Storage Service to the Query Service.
This is a component of each Storage Service which generates HTML forms for the user to write MIRC documents. It communicates with the File Service to access the file cabinet.