DICOM (Digital Imaging and Communications in Medicine) is the industry standard for transferral of radiologic images and other medical information between computers. Patterned after the Open System Interconnection of the International Standards Organization, DICOM enables digital communication between diagnostic and therapeutic equipment and systems from various manufacturers.
Such connectivity is important to cost-effectiveness in health care. DICOM users can provide radiology services within facilities and across geographic regions, gain maximum benefit from existing resources, and keep costs down through compatibility of new equipment and systems. For example, workstations, CT scanners, MR imagers, film digitizers, shared archives, laser printers, and host computers and mainframes made by multiple vendors and located at one site or many sites can "talk to one another" by means of DICOM across an "open-system" network. As a result, medical images can be captured and communicated more quickly, physicians can make diagnoses sooner, and treatment decisions can be made sooner.
The DICOM 3.0 standard evolved from versions 1.0 (1985) and 2.0 (1988) of a standard developed by the American College of Radiology (ACR) and National Electrical Manufacturers Association (NEMA). To support the implementation and demonstration of DICOM 3.0, the RSNA Electronic Communications Committee began to work with the ACR-NEMA MedPacs ad hoc section in 1992. This committee, chaired by Robert Hindel, PhD, established the concept of the central test node (CTN), a central exchange point that obviated the need for vendors to make prearrangements in order to exchange images directly with one another. At the RSNA annual meeting and scientific assembly, held at McCormick Place in Chicago, images compliant with DICOM 3.0 reside on the CTN and remain available to all participants on the network, including those on the technical exhibit floors.
With funds from RSNA, the Electronic Radiology Laboratory (ERL) at the Mallinckrodt Institute of Radiology developed software that was the first of its kind to implement the written technical specification of the DICOM standard. The software was installed on the CTN for demonstrating the standard over a local area network in the infoRAD section of RSNA '92. Mallinckrodt produced more sophisticated software, which was demonstrated across a wide area network at RSNA '93. In January 1994, an improved version of this software was placed on the RSNA and Mallinckrodt ftp servers for free public access in the belief that access to the source code and documentation would provide users and developers a model for understanding the standard and for design considerations and a set of utilities that would be useful for initial testing in developers' laboratories.
The following organizations have been involved in support of the DICOM effort:
- American College of Radiology
- Mallinckrodt Institute of Radiology
- National Electrical Manufacturers Association
- Radiological Society of North America
CTN Demonstration Software in the Public Domain The current set of DICOM 3.0 demonstration software enables users to test whether their systems can exchange radiologic images and related data with other systems through the CTN. It is available from the Mallinckrodt ftp server at ftp://ftp.erl.wustl.edu/pub/dicom. (Use an FTP client or paste this URL into your browser window.)
Version 2.7 of the Mallinckrodt CTN software is available as of October 6, 1995, and can be found in the file ctn-2.7.tar.Z. This tar file contains full source code and Postscript documentation describing the subroutine libraries and applications that comprise the CTN software. You should also download the files "README.2.7" and "README.contents.2.7" before grabbing the full distribution. As time permits and the DICOM Standard evolves, other versions will be made available. Please note that the version numbers of the CTN software are designed to track features of the CTN implementation and not the numbering scheme designated by NEMA.
This software is specifically designed and implemented to run on Unix-based systems. Neither RSNA nor Mallinckrodt has PC-based or Mac-based software that implements the standard.
Comments and suggestions should be sent to the Department of Informatics at RSNA by one of the following:
E-mail: informat@rsna.org
Fax: (630) 571-7837
Voice: (630) 368-3762
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