Brian Burgoyne, MD

Desert Radiologists, Las Vegas, founded in 1966, currently comprises 27 radiologists, with three more scheduled to join the group in coming months. The practice is the largest in the Las Vegas area and provides service for three hospitals and one large integrated health delivery system, and it is planning to take on a fourth hospital in late 2002. Desert Radiologists has four outpatient facilities and expects to build a fifth center to serve the area's rapidly growing population. Ten radiologists staff the outpatient centers, reading approximately 230,000 studies per year.

Paul D. Bandt, MD

To improve its efficiency, Desert Radiologists contracted with eMed Technologies in 1998 for an ambitious project: installation of an on-demand, multisite PACS infrastructure. With this technology, no matter where an image is obtained, it is delivered to a centralized archive, from which diagnostic workstations or web browsers can quickly gain access to it. The transmission lines and bandwidths to support the WAN vary from site to site, depending on capacity and needs.

PRACTICE CHALLENGES

The outpatient equipment now in use at Desert Radiology indicates the breadth of those needs, in its case: one positron-emission tomography (PET) scanner, seven MRI units, five spiral CT scanners (some with multiple detectors), nine ultrasound units, an angiography suite, a stereotactic biopsy suite, six nuclear cameras, four dual-energy x-ray absorptiometry units, nine mammography units, six fluoroscopy units, four conventional radiography rooms, two tomography units, and a computed radiography (CR) unit. All of the cross-sectional imaging devices and the CR unit are connected by an eMed PACS.

For Desert Radiologists, the number of sites covered necessitated the synchronization of work flow across multiple sites. An on-demand architecture for PACS, whereby all studies are accessed by multiple users simultaneously from a central archive, has become commonplace for many hospital-based enterprises. Implementing this technology across a wide-area network (WAN), as Desert Radiologists has, is another thing altogether. Studies are pulled from the central archive using common work lists at individual workstations. Regardless of where one of the group's radiologists is working, he or she can effectively manage a share of the work load as if present at the facility where the study was acquired. This is intrisically more efficient than a routing-model PACS (or primary diagnostic teleradiology).

In the routing model, all studies would need to be pushed to every workstation to achieve the work-flow advantage that on-demand distribution offers. This is not practical, for a number of reasons. Duplication of effort is a potential problem, and network bottlenecks can be another. In addition, the location of subspecialty radiologists must be continually communicated to technologists so that studies can be routed to the appropriate individual. In the on-demand environment, radiologists access studies without regard for their location on a given day. The use of a central archive also facilitates comparison with prior studies, which can be presented automatically with the current case.

ON-DEMAND WAN PACS

Desert Radiologists has four outpatient facilities and plans to open a fifth to meet the needs of Las Vegas' growing population.

Implementing an on-demand PACS architecture across a WAN has its unique challenges. To ensure optimal performance, the buyer should be certain that the vendor has had experience with WAN PACS implementations. Desert Radiologists was able to look to its vendor for guidance, as the company's expertise in network infrastructure runs long and deep. The practice is also fortunate to have relatively inexpensive fiber-optic communication available throughout the city. The group connects its two major offices using asynchronous transfer mode (ATM) and its two smaller offices using T1 lines.

The Las Vegas carrier has plans to provide 1-gigahertz bandwidth shortly, at half the price of ATM. Compression is another factor to consider. With an optimal compression technique, performance can be maximized. The vendor's experience with wavelet compression helped the practice minimize any issues associated with reading images with 8:1 lossy compression.

Work flow and load balancing are critical to Desert Radiologists' success. Not only is the practice expanding geographically, but each new device also seems to perform the same study more rapidly and with higher resolution, producing more and more images. For instance, the group's CT units will now easily complete a chest-abdomen-pelvis study, with exquisite detail, every 15 minutes, all day long. Conceivably, each study will take only 5 to 10 minutes once the practice integrates its radiology information system (RIS) and PACS.

With more sites to cover, and the increasing complexity of its studies, the group relies on remote consultations with its colleagues more and more. For instance, only a few of the group's radiologists will read MR spectroscopy studies, and a limited number are interested in reading MR arthrograms and PET studies. Subspecialty reading is beneficial to patient care and allows each radiologist to hone skills in his or her areas of interest. It also gives referring physicians some consistency in the interpretation and allows the most efficient reading of a study. Without WAN on-demand PACS technology to facilitate this work flow, Desert Radiologists would not be able to offer consistently the same level of subspecialty expertise.

BALANCING VOLUME AND COST

The work-load balancing of subspecialty interpretations makes it possible for Desert Radiologists to stay at the cutting edge of new medical technology. The group's goal is not only to distinguish itself technologically in the marketplace, but also to render the best possible patient care. As a result, Desert Radiologists has installed the first lutetium oxyorthosilicate PET scanner in Nevada (and one of few in the United States).

Desert Radiologists has implemented eMed.net enterprise, a web-based imaging-results distribution system. With eMed.net enterprise, referring physicians have secure access to their patients' imaging-examination results through web-based computer clients. Images and reports are posted automatically to a secure server after studies are interpreted by radiologists. Referring physicians thus receive reports and images wherever and whenever they want them, the only requirement being access to a computer that has an Internet connection.

Desert Radiologists did not plan to pioneer an on-demand PACS over a WAN. The group initially wanted simply to be filmless in ultrasound and to have an accompanying widespread teleradiology network. eMed Technologies was the group's original teleradiology software and equipment supplier. In undertaking a conventional financial analysis, the practice was able to determine that the film-cost savings associated with PACS were surprisingly large, substantially defraying the cost of the system. Moreover, a PACS would eliminate the increasing costs of archival film storage for the growing practice.

All digital imaging devices are connected by an eMed picture archiving and communications system.

The installation of the on-demand WAN PACS and eMed.net enterprise web distribution have allowed Desert Radiologists to maintain an extremely high level of functionality as its imaging volume has vastly increased. From 1998 to 2000, MRI examinations increased 42.3%; CT, 39.4%; and ultrasound, 42.7%.

A large WAN PACS implementation cannot happen overnight, for many reasons. There are always budgetary constraints. Implementing in phases helps make PACS a more affordable reality. Organizations should work with vendor companies that can demonstrate a track record of modular, phased implementations. Desert Radiologists was successful in implementing its PACS solution by using an incremental approach, which the vendor was able to facilitate. The practice was able to start with a minimal amount of equipment and upgrade as demand grew. It is also best to purchase only what an organization's storage needs call for today, and scale the solution as imaging examination volume grows in the future. Network-attached storage is an excellent option. Not only are the images immediately available online, but the server can be easily scaled without downtime or system interruption in the future. Another reason for phased implementation is internal acceptance of the technology. Desert Radiologists was able to grow the system slowly and bring its radiologists up to speed at a comfortable pace. If it had started with a massive implementation across all of its sites, the staff would have been overwhelmed, and learning curves would have been difficult to accommodate.

The practice originally intended to be filmless in just ultrasound.

Naturally, not everyone in the group was sold on the introduction of PACS; now, after 5 years, not all radiologists are equally enthusiastic, but none doubt the importance of the system. There was a learning curve that was painful at times, as each radiologist had to adapt his or her style of reading to new constraints. Continued on-site training can be a very useful tool to help improve initial comfort levels with the technology, and can help drive ongoing acceptance.

Conclusion

The efficiency of outpatient operations has been helped greatly by the transition to soft-copy reading. The benefit of the practice's investment, however, truly comes from an on-demand implementation across multiple sites. It is self-evident that the PACS and work-load sharing have allowed a more efficient expansion into the group's new offices, which typically would have taken several years to reach the breakeven point. Desert Radiologists also uses its PACS in the evenings and at night to balance work loads between hospitals and to provide 24-hour virtual coverage from just one site. The practice is currently evaluating the possibility of brokerless RIS-PACS integration, including an integrated dictation system with voice recognition.

Brian Burgoyne, MD, oversees technical innovations within Desert Radiologists, Las Vegas.

Paul D. Bandt, MD, is president of the practice.