Enterprise Image Management: A New Dimension in Storage & Access

Hospitals nationwide are scrambling to handle what is literally a growing image problem—higher-quality, volume-rich imaging studies are pushing storage needs to the terabyte realm and beyond. Accessing these images from longer-term storage and across systems also is a growing challenge.

Increasing study volume, use of diagnostic images and more complex exams are driving these issues. According to a September 2010 study published in the Journal of the American Medical Association, between 1998 and 2007, the share of injury-related emergency room patients who received MRI or CT scans rose from 6 percent to 15 percent, based on a nationwide sample of more than 300,000 ED visits from the Center for Disease Control and Prevention’s National Hospital Ambulatory Medical Care Survey.

The Background section of the 2008 Canadian Association of Radiologists guidelines for irreversible compression in digital diagnostic images in radiology sums it up: “While the cost of storage is falling, the savings are largely surpassed by the increasing volume of data being generated. In addition, the cost of operating a digital environment with high performance and resiliency is rising and is exacerbated by factors such as … long or indefinite retention periods for digital images.

“Access to imaging data is becoming more widespread as regions/nations implement Electronic Health Record (EHR) solutions. Expectations for accessibility are changing, with physicians requiring access to images dating back many years, in near real-time.”

As more images from more sources enter the data stream, facilities are reassessing their archiving strategies with an eye toward higher demands in the not-so-distant future.

SAN and SONET

Maimonides Medical Center, the third-largest reaching hospital in the nation, generates approximately 210,000 imaging studies each year. “At the moment everything, including images, is kept on a SAN [storage area network],” says Steven J. Davidson, MD, MBA, FACEP, FACPE, chief medical informatics officer at Maimonides, in Brooklyn, N.Y. “We have a strategy for image archiving that we’re probably going to live with for the foreseeable future, but we are starting to explore alternatives.”

Currently, images are generated by radiology and the vascular lab and stored in the hospital’s Aspyra PACS. “The SAN provides all storage for our PACS. On-campus providers access images via web services tools in the Aspyra PACS, particularly for teaching and quick reference purposes,” says Davidson. “Off-campus providers do not send images to our image store, but our providers working at an off-campus location may use web services through our practitioner portal to access and view images and related reports.”

The future of image archiving at Maimonides may be linked to email archiving, he says. “We’re about to implement an archiving strategy for e-mail. Currently we basically hold all email in active stores that are accessed with the Exchange server, which is backed up as a routine part of the SAN management. Because of the record-keeping, the vast amount of internal communication about patient care, we really need to develop an archiving strategy.

“We looked at several vendors and decided to go with a CommVault enterprise backup system for email,” Davidson says. “This is relevant to images because we’re building the infrastructure for that email archive, and [Comm Vault] is interested in exploring the possibility of tackling our image archive.” But that’s a long-term project, he says, which may not start until the end of next year.

Currently, “storage is mirrored between the SAN in the basement of the hospital building and IT, which is 10 or 11 blocks away, [and] we have a SONET [synchronous optical network] ring that’s used in support of our PACS configuration,” Davidson says. The medical center recently moved to Eclipsys’ Sunrise Clinical Manager 5.0 EHR and Siemens registration and patient accounting system.

The SONET ring architecture has provided reliable uptime, says Davidson, even during the 9/11 disaster, when many New York facilities with offsite mainframes were down because they couldn’t connect. More recently, the hospital sold the ring to Verizon and now leases back capacity.

A cloud-based storage and archiving system is not on the horizon—yet—says Davidson. Maimonides leadership has occasional conversations about cloud-based services, but at this point, “it’s more conversation than anything else,” he says.  

The hospital offers PACS services beyond the institution via web-based services, according to Davidson. Radiologists, orthopedists and other specialists review images offsite over the web-based services provided by the hospital’s PACS.

When Maimonides implemented PACS in 1997, the storage medium was a RAID array. “We graduated from that to a DVD jukebox arrangement,” which boosted storage capacity, but not necessarily access: “each box only had one drive to read and write,” he says.

The image archive’s move to the SAN paralleled the exploding growth in the size of imaging studies, says Davidson. “Clinicians have gone from looking at several dozen images to looking at 300 images for each study, so there’s much more to store. Fortunately, the price of storage has fallen, so it’s worked out for us, until now, to keep everything on the SAN and double [save] it between the hospital and the MIS department.”

In addition to capacity concerns, compatibility is an issue, he says. As a large teaching hospital with owned ambulatory sites and a number of partnership practices, “people come here after having had imaging done at a facility elsewhere. They bring us a DVD, and we might be able to read it with the reader that’s built into the DVD disk, but how does one get those images off that disk and into one’s medical record when you’re making clinical decision based on those images?”

Maimonides uses Integrity’s web-based Medical Image Importer solution for importing and reconciling medical studies from CD or DVD for storing to a PACS or other DICOM device. The Integrity system reads and extracts several different kinds of images to input studies from other providers. “You don’t have the order linkage and all the other stuff that happens with the interfaces we have here, so you have to manually create a patient database entry and medical record number, but you can incorporate it,” Davidson says.

Cloud considerations

Catholic Healthcare West takes a three-tier archiving approach to medical imaging: Facilities within the 41-hospital network store all images on-site in facility PACS, immediately replicate to a Facility Image Cache (FIC) and to a Long Term Archive (LTA) within minutes. The image store on the facility PACS is nominal—90 days or less—says Scott Whyte, senior director of physician and ambulatory IT strategy at CHW. The FIC retains images typically for 18 to 24 months, and “after that, it exists only on the LTA and the LTA Mirror,” Whyte says.

With a growth rate of more than 30 percent per year, storage space is an issue even at CHW’s two LTA sites, with close to 500 terabytes of capacity each in Phoenix and Sacramento, Calif., he says.

Although there’s downward price pressure on storage, “it still ultimately hasn’t been to our advantage,” Whyte says. “Storage growth, netted against the savings we’re getting from decreases, it’s still more expensive. We need to think about some other strategies.”

“We wanted to look at both clinical and business trends within imaging—who was accessing studies when and where, what were some of the challenges with our current three-tier architecture in terms of cost, function, technology, and where might we go. With this in mind, CHW decided to conduct an evaluation of cloud-based storage, Whyte says. “Not that we immediately thought ‘OK, we’re going to move all 41 hospitals to cloud-based storage,’ but we knew this was an important trend in the industry, and it would be something that we needed to get experience with, learn about, and find out if it was going to work for us.”

CHW selected DiCOM Grid to pilot its cloud-based storage project, and cloud-based archiving was implemented at CHW hospitals in Northridge, Calif., in June 2009, and in Reno, Nev., in August 2009. Both hospitals had PACS but weren’t yet connected to the long-term archive. There are substantial costs involved in connecting to the Phoenix data center—including data conversion, transport, and FIC hardware and software. “So we thought, ‘this is an opportune time to try cloud-based storage for those two facilities,” Whyte says.

High capacity and lower storage costs are the benefits usually cited for cloud systems, but CHW realized another advantage to the system: business continuity—a critical consideration in a system with multiple points of failure. In the three-tier system, an appliance sits between the PACS and communication transport equipment; if a connection between the hospital and the data center is lost, “then even though the image is secure, currently we don’t have access to it, which impairs clinical care,” Whyte says.

“After we … started putting the system in, one of our sites did have a failure in their PACS, [but] they were able to immediately look at these studies in our cloud-based storage system. We didn’t plan to use it for business continuity right away, this [happened] very shortly after the go-live. So that was a good proof point that the strategy does pay off,” says Whyte. Open architecture, standards and interoperability are critical to archive management. “Standards like DICOM and HL7 are tremendously helpful, but there are areas of standards that are open to interpretation. Our long-term archiving strategy, a single-vendor solution [built on Merge technology] simplifies that, but we have five different radiology PACS vendors as well as multiple oncology and cardiology solutions. We have to be able to talk to all of them,” he says.

Workflow is another challenge, according to Whyte. “This is not just a matter of copying data to the cloud. These are real people providing care, real people entering data related to the provision of that care, real patients that … have to be matched to the Master Patient Index. Those types of merged transactions have to be passed to the radiology information system (RIS), and also to the PACS, and how are those handled in the cloud storage? How do you make sure the data integrity flows all the way through the system? This is just one example that happens in the workflow quite frequently but is difficult to implement from a technology perspective. Any cloud storage vendors have to have solutions for preserving data integrity of this sensitive clinical information,” Whyte adds.

“There’s a tremendous amount of design work that you try to look through: What are the use cases that could cause challenges with integration? Organizations must include not just PACS and storage vendors, but also RIS, ADT [admission/discharge/transfer system] and other vendors in the discussion,” says Whyte.

Currently, images are stored on spinning disk technology. “We have used other compression methods like JPEG lossless to increase the amount we can store. We also are looking at different tiers for storage; there are some that allow very rapid access to data, others that aren’t quite as high-performance but [are] still a cost-effective solution for images that are not accessed as often.

“We could keep growing [the three-tier system] and we are looking at that option. The challenge is not only do we have to hold images in our primary LTA, we’ve got to store them in the LTA mirror as well, so one of the items on the table is determining if we can use cloud-based storage as a backup to our LTA in lieu of the LTA Mirror, and have a service provider who is specialized in storage perform that function for us,” Whyte says.

Weighing options

Outpatient imaging facilities face many of the same challenges as their inpatient counterparts, along with a greater likelihood that their client providers have a variety of PACS and other imaging systems.

“We’re looking at a number of new archive strategies and are actively evaluating those options right now,” says Andrew Wuertele, chief operating officer at East River Medical Imaging, a New York-based outpatient facility that provides comprehensive services at five offices on the East Side of Manhattan. “Clearly, the end game is central data storage and unlimited access to the data [given patient’s consent], regardless of where it lives. That’s still a bridge that needs to be crossed.”

“Storage demands are increasing and we want to maintain records for infinity, and make sure they’re accessible to these systems… In some ways, the storage seems to be the commodity, but fast access to it on the cloud is the challenge.”

East River Medical Imaging uses GE’s Centricity RIS-IC/PACS-IW for workflow management, and the combination of RIS and PACS has enabled the practice to run more efficiently, says Wuertele.
“We have RIS/PACS linked to one of our providers that has the GE EMR system, and they are using the interface to send electronic orders and receive immediate results with linked images. With a hyperlink, they click and it opens up and they can just see what we’re seeing here in our office,” says Wuertele.

“We’re hearing from these physicians that their ability to be in their patients’ charts in conversation with their patient, and with two clicks to open the images, enables them to show and tell in a way they haven’t been able to before,” agrees Steven Albert, MD, radiologist at East River. “It would take too long to sign in to another system and search for that patient’s image set and pull everything up separately or load a CD into the system. Now they’re within their own EMR chart system, and there [are] the pictures that are leading to the patient’s next step.

“The economics of storing and the requirements for memory have been surprisingly inexpensive, to me, within our facility,” agrees Albert. “There’s no doubt that ultimately, you want to get to where a patient in Manhattan may have one study with us … then end up in another office somewhere else [and still access their study]. Although they are all digital data, if they are not sitting in a place where they are all accessible, ultimately you’re not doing the patient a service.”

Security is another concern, both for patients and for the archiving facility. “The question is, who controls [an image], and how it’s controlled is probably an economically driven issue at the moment as well as a HIPAA and a security issue,” says Wuertele. “Patient records and their security is a real hot button for people and we can even see, within our office, patients’ real concern about their information being accessible to their employer, their friends or the family, so it’s got to be done carefully. But I think it has to be done.”

“Who owns the information and therefore the politics around protecting that sense of ownership creates the largest hurdles to sharing information across platforms,” Albert says.