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
Phoenix Children's Hospital, which opened as an entirely filmless facility two years ago, employs a similar ongoing rolling evaluation of its storage needs - with different results. Radiology Director Harry Dower says, "In the old days of film, archiving was easy. You put your films in a warehouse offsite and hoped that you could find them in 25 years if needed." Physically eliminating film brings a technical challenge.
As a new facility with relatively low imaging volume, Phoenix Children's calculated that it did not have the imaging volume to warrant purchasing its own storage solution. The hospital opted to use an ASP and pay a one-time fee per patient for storage. One plus of the ASP option is that the company is responsible for locating images as they are required in the future. The downside, however, is economics.
"As our volume increases [from the current volume of 56,000 studies annually], the ASP route will get more and more expensive," Dower explains. "There is a line where it becomes more economical to purchase our own storage." Currently, Dower calculates the line at 110,000 to 115,000 procedures annually. That calculation, however, is a moving target as the price of storage technology continues to drop.
Another option that the hospital may explore is an enterprise-wide SAN for data storage. Enterprise-wide SAN links several servers with several storage solutions and allows users to share resources and data. Dower estimates that SAN would cost about $6.50 per patient for charts and images, which is about what the hospital pays currently for image storage. This solution may make sense on a number of fronts: economics, patient care and efficiency. Dower explains, "There is really a push to keep all electronic records together. Physicians want to look at x-rays and lab results and medications without flipping through five or six screens. Organizations are moving to the one chart/one place mentality and enterprise-wide SAN makes that so much easier."
THE BIG PICTURE
The annual imaging volume at Children's Hospital Boston tops 150,000 procedures, so it clearly made sense to purchase an archiving solution. One of the key questions that hospitals need to address is access. Treves asks, "Do all images have to be online?"
For most hospitals, the answer is no. A graded archiving strategy makes sense. This model adjusts rapid access to length of time from the study. That is, the more time that passes from a study, the less likely it is that the image will need to be required with urgency. The hospital can migrate those older studies, typically after a year or two, to less expensive storage.
Children's Hospital Boston selected Clariion, EMC's SAN platform, for networked storage for short-term storage of PACS images. EMC Centera provides back up and long-term archive for PACS images and electronic medical records. Treves says physicians can retrieve archived images from Centera within seconds, greatly enhancing the clinical decision-making process compared to the previous film-based archive. The system also will help the hospital meet its goal of online access to patient history for 25 years after the last hospital visit.
Treves says the storage solution is one part of the entire digital workflow picture that includes everything from PACS to voice recognition to reading room ergonomics. "Our access to information is fantastically wide and fast. We don't waste time with lost images anymore. We have access at our fingertips and available throughout the hospital online."
Archiving in the Pediatric Cath Lab
Although patient volume may fall short of adult cath lab operations, the cath lab at Children's Hospital in Omaha is fairly busy with 330 pint-sized patients visiting the lab annually.
Last year, the hospital built a new state-of-the-art cardiac cath lab. The new lab provided the opportunity to implement a new cardiac image management system. Stacey Froemming, RCPT, lead technologist at Children's cardiac cath lab, says a
primary concern was finding an archiving system that could handle massive amounts of computer data and large volumes of images. The hospital acquires all cardiac cath images at 1024 x 1024, with the average pediatric study being 10 to 20 cine runs. A biplane exam could entail 2 million pixels per frame. The ability to store that amount of data is a key consideration, but rapid retrieval is equally important. A pediatric cath patient could return to the hospital several times over the course of a year, and without fast access to current and prior images, clinicians cannot make rapid, informed treatment decisions.
The hospital analyzed a number of factors when selecting its cardiac image management solution: image quality, archiving media durability, speed of retrieval, flexibility and HIS network integration. Froemming reports, "There are a lot of good archiving systems on the market. You can slap a digital archiving system on just about any angiographic system. We felt it was important to find imaging and archiving vendors that could work together to create the best system possible." The hospital opted for a Heartlab Encompass ELS filmless image management system to complement its Toshiba cath lab equipment. Froemming believes the hospital benefits from the established relationship between the vendors, with nearly seamless image transfer from the cardiac x-ray systems to network-connected diagnostic review stations.
The Encompass system provides immediate storage for 60 patients on its hard drive. As the hard drive fills, images are automatically moved to a 250 DVD jukebox. Froemming reports that physicians can retrieve historical images from the DVD archive in 4 seconds.
An archiving system should enhance patient care, and the Children's system meets this goal. Unlike film and tape, digital records never degrade over time. "When we do have to bring patients back to the cath lab, this system easily allows us to look at prior images and see how things have changed," says Froemming. "Ultimately, this makes for better patient care."