A case of revolution rather than evolution, and the breakthrough comes thanks to a grid-computing architecture created at the University of Southern California (USC). Such a network will enable doctors to request second opinions from specialists at any location, while the ability to share images easily could speed the review process and help to eliminate backlogs. Critically, the system will also allow closer monitoring of ongoing clinical research, as well as enabling doctors of young cancer patients to quickly spot any treatments that aren't working and change course accordingly.

Medical images and associated information are generally produced and stored using the DICOM (Digital Imaging and Communication in Media) standard. Employed in virtually all hospitals worldwide, DICOM provides a uniform electronic image format that enables a wide range of equipment - such as X-ray, MRI and CT systems - to display and manage images from any other device.

Unfortunately, owing to technological, administrative and confidentiality challenges, DICOM's potential for transparent exchange between collaborating institutions has yet to be realized. As a result, access to all of these interchangeable data has to date been limited to the hospital where the images were acquired.

"Today, if you leave the hospital, you either leave your digitized images behind or you have to carry them on a CD-ROM," said Stephan Erberich, director of functional imaging and biomedical informatics at Childrens Hospital Los Angeles (Los Angeles, CA) and faculty member of the USC Keck School of Medicine and the USC Viterbi School of Engineering.

"This is not the 21st-century health care we need in a networked society," Erberich added. "All kinds of other fields, from banking to air travel, now rely on instant information exchange and decision making online. We should be able expect the same level of sophistication in health care."

Share the work

With this goal in mind, Erberich turned to the Globus Alliance. Globus is an international collaboration dedicated to developing the technology, standards and systems that form the Grid, a networked computing architecture that lets users share computing power, databases and other online tools securely.

Erberich, a computer scientist, teamed up with Grid experts Carl Kesselman and Ann Chevernak from the USC Viterbi School of Engineering's Information Sciences Institute (Marina del Rey, CA) to create Globus MEDICUS. The Globus MEDICUS project makes paediatric cancer researchers and the medical imaging profession the latest in a growing number of communities to exploit the Globus open-source Grid software.

The scientists designed the system so that DICOM records at any medical facility can be easily accessed and exchanged over Grid-secured Internet connections, using the DICOM Grid Interface Service (DGIS). The key to the development was marrying the DICOM and Grid technologies.

"There had to be new code developed to handle the medical-specific things like DICOM translation and patient confidentiality assurance," said Kesselman, who has previously helped scientific communities – from high-energy physicists to geologists – to share instrumentation and data. "But the cool thing is that this leverages all of the existing underlying Globus technology that we use in so many other projects."

Another impressive selling point is the low set-up cost of installing a DGIS node: approximately $1000 for a Grid gateway attached to a high-bandwidth Internet connection. Such a gateway provides two-way access to the Grid, allowing upload of local images (after "de-identification") as well as continued access to a catalogue of archived DICOM records.

One dramatic change in practice will be the ease of review of images. Clinicians and researchers can look at observations made anywhere on the Grid without leaving their offices. "We store the images here in the data centre, but the people who have been assigned to review images can review them from virtually anywhere," said Erberich.

"Before, when we were documenting a research study, radiologists would have to physically come to a single facility and look through a file cabinet full of physical images," he explained. "Now, radiologists all over the planet can look at the images at their leisure in their own offices, on their own favourite commercial medical imaging system."

The system has been up and running since September and is currently in use at 40 North American hospitals: the 13 institutions in the New Approaches in Neuroblastoma Therapy consortium, plus the 27 members of the Children's Oncology Group. Each facility is connected to the Grid using one interface per site that serves the whole hospital.

With such a low entry cost, and the possible applications only beginning to be tapped, both the doctors and the computer scientists involved expect the number of sites connected in this way to skyrocket in the coming years.

Erberich is demonstrating the Globus MEDICUS system at the annual meeting of the Radiological Society of North America (RSNA) in Chicago, IL, this week.