It's Working for Healthcare Worldwide

An important message from the ACR and NEMA Digital Imaging and Communications Standards Committee

What is the DICOM Standard?

The Digital Imaging and Communications in Medicine (DICOM) Standard is a detailed specification that describes the means of formatting and exchanging images and associated information. The standard applies to the operation of the interface which is used to transfer data in and out of an imaging device.

DICOM relies on computer industry standard network connections and addresses more effectively the communication of digital images from diagnostic modalities beyond CT and MR including nuclear medicine and ultrasound (contributions from corresponding NEMA sections), and also computed radiography, digitized film, video capture and HIS/RIS information. It also supports the connection of networked hardcopy devices.

DICOM is the result of an alliance of potential users of the standard (members of the American College of Radiology - ACR) with the companies that manufacture medical equipment (members of the National Electrical Manufacturers Association - NEMA) that began in 1984. DICOM has also been embraced by other worldwide standards organizations and other healthcare disciplines outside of radiology. These additional inputs to the DICOM effort have made extensive contributions to its success.

The DICOM standard has now been implemented in an increasing number of medical products of various vendors. The rapid adoption of DICOM by the medical imaging industry is opening new opportunities for health care organizations to increase the quality of patient care and cost effectiveness of the handling of and access to images and associated information.

Why do we need a standard interface?

A means is needed to get digital image data and associated information into and out of imaging equipment, whether it be an acquisition system, an archiving system, a display workstation, or a hardcopy device. Without an industry standard, custom interfaces are needed for each imaging device. Currently, in a typical, multi-vendor imaging department, there is little compatibility of equipment, so custom interfaces are developed or purchased in order to interconnect the equipment. When DICOM is built into a medical imaging device, it can be directly connected to

What does a manufacturer do with the DICOM Standard?

A manufacturer uses the standard to design and build a product. The DICOM Standard describes all of the detailed functional specifications which a device with a communications interface (allowing one computer to "talk" to another computer) must employ to meet the standard. The standard provides a common reference for all developers yet does not impose a single implementation, thus allowing for innovation.

Some implementations of DICOM may still require the purchase and installation of a circuit board and software for the imaging equipment. This approach is analogous to a cable television converter which connects to the company cable on one side and provides standard video out on the other for connection to a television set. An alternative is to integrate the DICOM interface into the imaging equipment. This is analogous to a cable-ready TV receiver where no accessory cable box is required as the circuitry necessary to do the translation from cable to video signals is built into the TV.

In either case, the interface uses a set of computer software (programs) which operates in the imaging equipment or accessory box (or both) and executes the DICOM protocol. The programs also format the data for transmission. DICOM takes advantage of computer industry standards to provide a network connection with other devices. This allows easy connection of DICOM conformant imaging equipment to exist in hospital networks supported with off-the shelf networking hardware and telecommunications services, and covering a broad range of networking configurations. Intra-hospital connections, communications with remote clinics and teleradiology applications are facilitated.

How can I use DICOM if I don't have a PACS?

DICOM is a valuable tool even if your department does not plan to install picture archiving and communications system (PACS). In a multi-vendor environment, DICOM can be used to connect specialized systems, such as 3-D image processing workstations, teleradiology systems, and hardcopy devices. Introducing DICOM is often a simple task, and selecting DICOM compatibility today will facilitate future PACS installation.

What is the current status of the DICOM Standard?

Approved in November 1993, the DICOM Standard is available as NEMA Standards Publications PS 3.1 through 3.9. Key features of DICOM include:

Work continues on many useful supplements to DICOM which extends its usefulness to other medical disciplines, such as Endoscopy, Radiation Therapy Planning and Pathology. Working groups continue to be created by the ACR-NEMA committee (the joint committee formed by ACR and NEMA in 1984 to develop digital imaging communication standards) at the request of various interested parties to address extension of the standard in useful ways.

DICOM has made great strides since the initial demonstrations of basic capabilities at RSNA 92. Since then, numerous demonstrations of DICOM have occurred at various international forums, including SPIE, EuroPACS, CAR, JMCP, ECR, ACC, and every RSNA meeting since 1992.

DICOM products have been available from many manufacturers since RSNA 93. At RSNA 95, over 40 vendors participated in the DICOM demonstration with their DICOM solutions.

The DICOM standard is internationally recognized for medical imaging. The European standards body (Comite European de Normalisation) CEN TC 251 has adopted DICOM for the European Standard MEDICOM. The Japanese Industrial Association of Radiation Apparatus (JIRA) has based the new version of its MIPS standard on DICOM. ACR and NEMA participate in various cooperative efforts, including the American National Standards Institute Healthcare Informatics Standards Planning Panel, which coordinates the work of all the major healthcare standards bodies in the United States, and provides formal liaison to standards organizations beyond the USA.

Why the name DICOM?

Version 3.0 of the ACR-NEMA standard is called Digital Imaging and Communications in Medicine or DICOM Standard to reflect the contribution of other international organizations as well as the standard's ability, to expand beyond the sole support of radiology images. Examples include the adoption of DICOM for images from cardiology, endoscopy, surgery and pathology.

DICOM embodies a number of key features:

Does DICOM address interchange of images on digital recording media?

Supplements to the DICOM standards for the exchange of images stored in digital form on media such as optical disks were completed during 1995. The ACC actively participated in this work, and there was extensive cooperation with JIRA and MEDIS-DC in Japan on this effort. One of the first targeted applications is the exchange of x-ray angiographic studies on a recordable compact disk (CD-R). A prototype demonstration of this capability occurred in March 1995 at the ACC meeting, and an additional demonstration is planned for March 1996. Manufacturers have already announced products using these new DICOM supplements.

What has been demonstrated at RSNA in December?

One of the highlights of RSNA 95 has been the network connectivity demonstration of products and prototypes based on DICOM across the commercial exhibits. Forty different companies have participated in this demonstration and connected one or more of their imaging systems on the RSNAnet and accessed the RSNA DICOM Servers. These servers were developed for RSNA by the Mallinkrodt Institute for Radiology (Washington University, St. Louis, MO, USA).

This demonstration built upon the successful RSNA 1992 through 1994 demonstrations and proved the expanding maturity of DICOM implementations.

Key features of the demonstration included:

Where does DICOM go from here?

The DICOM standard has now been implemented in a large number of medical products of various vendors and validation is on-going between vendors in order to verify proper implementation of the standard. NEMA has formed the Committee for the Advancement of DICOM to specifically promote and facilitate the use of the standard. One activity of the committee is the development of a suggested Guideline for the testing of DICOM-equipped products, which is to be publicly available in early 1996.

Because of the availability of DICOM in products, users are now realizing the real benefits of the standard, which is INTER-OPERABILITY - the ability to provide applications and functionality over a network. Now functionality that was only available within the constraints of products of a single vendor, has been proven to exist in a multi-vendor environment. This was one of the main objectives of the standard, but now radiologists and physicians are beginning to experience this benefit.

Among users, an new question has arisen: "Now that I have DICOM, what can I do with it?"

Discussions have moved from "how" to "what". This new awareness with the users of medical equipment is driving the development of products for new applications, beyond the traditional methods of the past. This will result in improved efficiency of healthcare delivery.

This new awareness is facilitating better cooperation between competing suppliers of medical equipment, since the users of equipment are now expecting interoperability in their new equipment.

DICOM is a joint effort of users and manufacturers, and it's working!

Where can I find out more?

The DICOM Standard may be obtained be calling NEMA Customer Service at 703-841-3200.

At RSNA 95, information about DICOM was available from vendors taking part in the DICOM Demonstration.

DICOM will also be discussed and demonstrated at several international meetings in 1996, including SPIE, SCAR, CAR, ACC and RSNA 96.


Ms. Vicki Schofield, Industry Manager, NEMA 1300 North 17th Street, Suite 1847, Rosslyn, VA 22209, USA/ Phone: (703)841-3281; fax: (703)841-3381,

Mr. David Snavely, Industry Manager, NEMA 1300 North 17th Street, Suite 1847, Rosslyn, VA 22209 USA/ Phone: (703)841-3285; fax: (703)841-3385, dav_snavely.

Mr. Jim Morison, Deputy Chief Operating Officer, American College Of Radiology, 1891 Preston White Dr. Reston, VA 22091, USA/Phone: (703)648-8900; fax: (703)648-3240,

Prepared by the ACR-NEMA Digital Imaging and Communications Standards Committee, with support from the American College of Radiology and the MedPACS Section of NEMA whose members are: