Diagnostic Imaging
March 2004

OVERREAD

ASPs return to radiology realm in a different format

Increasing utilization will benefit patients with head injuries but could also increase costs

Application service providers may be making a comeback in the radiology department. The high-flying ASP days were brought to an end by the dot-com bust, and many observers wondered how long the model could survive. The University of California, Los Angeles Medical Center has taken another look, but they have added a twist: a nonlinear ASP financial model for PACS data storage.

"What we were looking for was a large-scale reduction in capital costs," said Dr. Osman Ratib, vice chair of information systems at UCLA.

In a scientific presentation at the 2003 RSNA conference, Ratib compared the purchase cost of onsite digital archives with that of an offsite ASP storage model. Onsite digital archives require a large capital outlay for the initial purchase, followed by steady maintenance costs, he said. These regular maintenance levels are punctuated by periodic spikes in capital expenditures for system upgrades.

In the traditional linear ASP financial model, users pay as they grow. This model would not have worked for his institution because the total cost of ownership would eventually have exceeded that of the onsite financial model.

The nonlinear alternative ASP financial model takes into account the fact that storage costs decrease year after year, while storage technology continues to advance. UCLA paid a single price per study, but the vendor provided a 4% decrease in storage costs per year. This was balanced by the requirement that UCLA increase its study volume by 5% each year. Based on this setup, Ratib calculated a lower total cost of ownership for the nonlinear ASP model.

The ASP archive is also completely scalable, and obsolescence is not a concern because hardware and software updates are the responsibility of the ASP provider. Savings come from reduced personnel costs and limited capital costs at the outset. But challenges remain.

"One of the difficulties we encountered was the migration of generations of legacy data," Ratib said.

During the transition to a new PACS and an ASP model of data management, the medical center migrated 20 TB of data from legacy PACS to the new system. More than 28 million images needed to be transferred, and the hospital still was generating new data and images at the rate of 160 GB a week.

Prior to image migration, Ratib and colleagues began extracting data from the legacy databases and consolidated them with an updated extract of the RIS database. The new PACS featured a direct interface to the RIS. Data migration for the most recent four years of data took more than three months to complete, and many people worked behind the scenes double-checking the data to ensure quality control.

The ASP model is not without risks, he said. Hospitals must make a long-term commitment to a single vendor. During long, complex contract negotiations at UCLA, parties agreed the vendor would have no legal liability for clinical errors or complications resulting from data storage.

Ratib cautioned those considering an ASP solution to stipulate during contract negotiations that the medical institution is the sole owner of the data and that the ASP provider cannot do anything to or with the data.