Archiving pediatric images brings some unique challenges, with storage requirements of up to 25 years driving the business. In the film-based environment, this typically meant stashing films in an offsite warehouse. But as hospitals transition from film to digital, a proactive image archiving strategy can help develop a cost-effective, efficient, HIPAA-compliant pediatric solution. For many sites, enterprise-wide SAN provides a short-term solution for PACS image storage. And children's hospitals across the country are deploying content-addressed storage as a cost-effective, yet readily accessible, archiving system for static medical images.
Time is perhaps the largest challenge of archiving pediatric images. Since many images need to be kept for 20 to 25 years for legal reasons.
"The major challenge with pediatric images is the number of years images need to be kept," says S. Ted Treves, MD, chief of the division of nuclear medicine and vice chair of information technology for Children's Hospital Boston Radiology and Information Systems Department. Although regulations vary by state, pediatric images must be stored for 20 to 25 years compared to about seven years for adult images.
Daniel Morreale, CIO for North Bronx Healthcare Network, explains the implications. "We can calculate how much storage we need now, and we know our storage needs will grow geometrically. Over the next 21 years, the nature of diagnostic tests will change dramatically. We know we'll need to store an astronomical amount of data." Morreale poses an answer to the long-term dilemma. "The only answer is to make yourself [and archiving solution] as flexible as possible."
The short-term pediatric archive situation is also a bit vexing. Pediatric image volume can be relatively high. Because pediatric patients are growing and changing rapidly, they are typically imaged more frequently than adults. And then there are 3D reconstructions, moving ultrasound clips, 3T MRI and 4-, 8-, 16-, 32- and 40-slice CT scanners yielding massive amounts of data to be stored. "We are in the gigabyte per study range, especially in nuclear medicine and cardiology," Morreale says. "I could easily use a terabyte of storage a year in cardiology alone." Although storage costs are dropping, increasing demands for archive space could negate future cost decreases. Finally, access must be considered. Like all other providers, pediatric caregivers need rapid access to images to make quick decisions.
THE ROLLING STRATEGY
As hospitals evaluate pediatric archiving solutions, it is important to determine how much capacity is required. Treves recommends a rolling strategy. The hospital starts by calculating the terabytes required to store and archive its annual digital image volume and purchasing two to three years of short-term storage based on this calculation. For example, if the hospital calculates that it requires 10 terabytes of storage for one year's imaging data, it may plan for 30 terabytes over three years. Revisiting the plan on an annual basis is critical. Treves explains, "Every year the hospital should review the number of procedures and add to the archive based on needs, so that the hospital doesn't fall short of storage at the last minute."
Jay Moskovitz, PACS system administrator at Cincinnati Children's Hospital Medical Center, points out, "It doesn't make sense to buy storage for more than three years because the technology changes so rapidly; costs are decreasing and options are improving." When Cincinnati Children's first deployed PACS a few years ago, it opted for WORM drives with optical disks that held 4.5 gigabytes of data per disk and a 500-slot jukebox. When the hospital needed to purchase additional storage recently, it implemented a new MOD archive that can store 9 gigabytes of data on a disk.
The hospital plans to implement the EMC Centera and provide 17.5 terabytes of offline storage with the new archive platform. Janet Beerman, manager of radiology informatics, says the plan is to migrate all PACS images to Centera and use Centera as the primary archive. A Plasmon archive, which holds 630 disks, will serve as a disaster recovery archive as required by HIPAA. Finally, the RAID provides three terabytes of on-demand storage; images will remain near-line for about one year at the hospital. While Centera has not yet been deployed, Moscovitz predicts that users will not perceive any differences in retrieval time among the three archives.
THE ASP MODEL