When John Mowry, digital imaging manager at Cook’s Children’s Health Care System, Fort Worth, Tex, decided to switch from his legacy PACS to a thin-client, Web-based model, he faced a particularly daunting migration situation. The servers in use by the legacy system were on their last legs; meanwhile, there were more than 10 million images across 450,000 studies to migrate. “The situation was dicey at best,” Mowry recalls. “It had come to the point where the system was so old and the support was so bad that we couldn’t even run the servers half the time.”
Dicey is probably the most generous thing that can be said about old PACS technology by the time most IT departments begin the migration process. In today’s cost-conscious health care marketplace, the switch to a state-of-the-art solution is often delayed until the legacy solution is demonstrating serious weaknesses. “The company operating the legacy system was in financial straits at the time we decided to switch,” Mowry says, “and their PACS wasn’t scalable to handle the load of exams we were doing at the time.”
In addition to scalability, Mowry’s PACS shopping list included the following: he wanted the vendor to be an established, financially sound company, he wanted to be able to link the system to the hospital’s electronic medical record (EMR), and he wanted a Web-based solution. “No matter where you sit down, you’re able to access the PACS,” he says of the Synapse system from FUJIFILM USA Medical Systems, Stamford, Conn. “Anybody who uses our hospital information system (HIS) and has access to the EMR can pull up an image at any time.”
Clearly, the switch was worth the trouble. As a veteran of the dreaded migration process, Mowry has some valuable advice for anyone in his situation: plan ahead. Assess how much data you have to migrate, look at what kind of data storage you’re currently using, and make sure you know the format in which your images are currently stored. “It was a very in-depth process for us,” he says of preparing for migration. “It took about two and a half months to migrate the data. We spent a year preparing and planning.”
Preparing the Way
Preparation shouldn’t involve just an assessment of the current system’s characteristics, which most IT personnel are all too familiar with anyway; it’s equally important to consider the system to which you’re going to be migrating your data. Mowry recommends ensuring that you have a minimum of three times your current storage in order to allow for future growth. He also suggests moving to spinning media if your current storage is DVD- or tape-based prior to migrating to the new PACS, with one caveat: know that this process may require the assistance of your current vendor.
“We had cooperation from our existing vendor in moving data from the DVDs to spinning media,” Mowry says. “The company created some jobs for us that we ran a few at a time, every three nights, to move the data from the DVDs to the storage-area network.” The transfer dramatically shortened the PACS-to-PACS migration to less than three months.
Migration costs are generally built into the contract with the new vendor, which plays a crucial role in the process by providing the migration server that queries the existing PACS for data. The querying process is followed by the migration itself, which occurs study by study and can be particularly rough on outdated, overworked servers. It’s the catch-22 of the migration process: The best justification for upgrading to new technology is the difficulty of making the change.
“Our migration server started at day 1—July 15, 1999—and started pulling studies one by one into the new Fuji database,” Mowry says. “Our servers were getting old, and we weren’t sure they’d be able to handle the additional workload of this daily job and migrating all the new data, so we started slowly and gradually cranked it up until it was moving three or four studies at a time.” Though he was concerned about this process inhibiting access to prior studies during the migration period, in the end, there were no problems using the legacy PACS.
Mowry recommends a slow, gradual testing process, using a test server, prior to beginning migration in earnest. The aspects to be tested include display of all studies transferred from the old PACS to the new PACS and the display of all images sent from each modality to the new PACS.
All told, the migration took approximately two and a half months. “We know of