Q: Why is DICOM important?

DICOM is critical as a means of exchanging information between imaging devices and imaging systems. DICOM provides a uniform language to exchange information.  It provides a standard way so that when you have a PACS [picture archiving and communication system] from manufacturer A and a CT [computed tomography] scanner from manufacturer B and a ultrasound machine from someone else, that all of these systems are able to speak to one another. That was the original goal and vision for DICOM, and that continues to be the focus.

Q: Was that a problem in the past that these machines couldn’t communicate with each other?

Absolutely. Because each manufacturer worked independently and in competition with the others, each had a proprietary approach to connecting their equipment. In the 1980s, the American College of Radiology (ACR) and the National Electrical Manufacturers Association (NEMA) began developing a standard that used a 50-pin connector and was developed for point-to-point interchange. As computer network standards—especially the Ethernet protocol—were developed, it became feasible to develop a network-based version of the ACR-NEMA Standard. So from the very beginning, the whole goal of DICOM was interoperability.

Q: Has the situation improved since the original release of DICOM?

It’s incremental improvements. What’s happened is that as imaging has grown and become an increasingly important part of healthcare, the DICOM standard has grown, too. So, for example, initially DICOM was concerned with plain x-ray, such as radiographic images, CT and ultrasound, but now the standard encompasses many other areas, such as angiography and what is termed “visible light,” which includes endoscopy and images of tissue slides. The goal of much of this is to have digital images, tissue slides that could also be transmitted and sent in the DICOM standard. So it’s not just people sending JPEG images by email back and forth. The idea is you send a DICOM image that comes with all the identifying information about the patient, it has the security layers and it can have structured reporting information embedded in it as well.

Q: So using other formats like JPEG doesn’t work?
 
Actually the DICOM standard uses parts of other standards, such as JPEG 2000. In other words, the goal of DICOM isn’t to reinvent the wheel. Wherever possible, DICOM takes advantage of existing standards that are in place and in use in commercial systems and in off-the-shelf technology. JPEG itself is an excellent standard for image information, but medical images include a large amount of metadata that describe factors such as the patient, the date and time of the study, and how the image was produced.

Q: Are there other standards like DICOM?

For medical images, DICOM really is the standard. Other standards, such as Health Level Seven (HL7), are used to exchange messages between health information systems. DICOM is an open standards effort that has grown out of the collaboration between the ACR and NEMA. Today, DICOM is much broader than just radiology. Working groups within the DICOM organization are very active in developing parts of the standard in cardiology, ophthalmology, pathology, dentistry, surgery and veterinary radiology. 

Q: How prevalent is the standard?

Generally when a hospital or medical group solicits proposals to buy imaging equipment, they require DICOM. These days, it would be most unusual for someone who purchases equipment not to require the vendor to have that equipment incorporate DICOM and meet the standard.

Q: What changes have been made in the 2007 version of DICOM?

Among the things that are in there are so-called enhanced CT and enhanced MR [magnetic resonance] objects. These enhanced objects allow CT and MR images to be displayed in more sophisticated ways. DICOM also incorporates standards for hanging protocols, which specify how users can view the images, and for three-dimensional image data.

Q: So it supports how users would want to view that information?
           
Exactly. And it allows us to take advantage of the ability of CT and MR scanners to generate multiple series of images while letting us view those more intelligently.

Q: Is work being done on the next version?

There are a number of things underway. Again the idea is that as the imaging technologies and the information and communication technologies advance, we’re all working to keep up and incorporate that into the standard.

Q: What made you decide to get involved in developing DICOM?

I invest my time because standards efforts, such as DICOM, are extremely important to the practice of medicine. Imaging really has become central to medical practice. When a patient comes to the emergency room, often the piece of information that yields the greatest diagnostic value is some imaging test. It’s by means of the DICOM standard that information gets sent from the CT scanner to the workstation where the radiologist interprets the images, then down to the emergency department where the emergency physician can view the images and the radiologist’s report within minutes of the study being done. By making the flow of information seamless and unambiguous, we can improve the delivery of health care, and improve the health of our patients.