As medical imaging technology improves and more clinicians demand access to patients' diagnostic-quality images, healthcare providers are finding that storage requirements are soaring.
In the past, radiology and cardiology departments were the primary users of medical imaging systems and picture archiving and communication systems (PACs), including CT scans, MRI, cardiac catheterizations and echocardiograms. But recently medical digital imaging has exploded into many more specialties.
Pathologists and dermatologists are among the new users. Images of tissue samples and skin lesions improve diagnosis and track the progress of patients' treatments. Also, new cancer diagnostic exams involving the latest medical imaging equipment, such as digital mammography, produce thousands of images per study.
About five to seven years ago, the average 300- to 500-bed hospital needed about 1 to 2 TB of storage for its medical imaging, says Matt Long, North American VP of enterprise imaging at Philips Healthcare, a provider of PACS products and services. Today, it needs 50 to 100 TB for the average 150,000 to 200,000 imaging-related procedures done annually in those sized facilities, says Long.
Annual storage requirements for many providers are increasing at a rate of 20% to 100%, says Gary Sevounts, senior director of product marketing for Symantec's electronic health group. A CT scan that in the past had 8 slices, or images, can now have 256 or more slices. "That's many times more than the older images," he says.
Ballooning storage requirements has resulted in a number of challenges, from cost to disaster recovery to security and access issues, Sevounts says.
Digital image storage space isn't easily reused. Retention rules for medical images vary from state to state, but generally, providers are required to keep images for at least seven years. When it comes to oncology centers, many hold on to these images for the life of the patient and beyond, Long says. That's because cancer doctors as well as researchers are using the images to track how patients' tumors respond to various treatments.
Also, while the cost of raw storage is decreasing, the associated costs for staff to track and manage images, management software, disaster recovery and backup systems, and the energy to power these systems are soaring, Sevounts says.
"As more and more images are being created, they're not just the property of the radiology department, other clinicians want access," Philips' Long says. "It's no longer a storage problem, it's an access problem." Storing images on tape or optical drives doesn't provide quick access, he says. Instead, hard disk storage is needed for quick online access, he says.
Doctors using electronic medical records especially expect easy access to patients' heart, dermatology, and pathology images, he says. The challenge for providers is how to provide that access easily and securely, he says.
Some healthcare providers are using different approaches for different departments' imaging needs, says Ben Brown, general manager of imaging informatics at research firm KLAS. Short term images--less than 6 months to a year old--will generally be stored on disk devices for quick access, but for longer-term storage, images are archived on tape or optical. Older images need to be requested in advance of seeing a patient so they can be retrieved from storage, he says.
Other providers are standardizing on one PACS to take advantage of economies of scale and so they can consolidate and virtualize storage. Hospitals are also turning to outside companies for offsite storage, archiving, and management of images. In those cases, healthcare providers pay per use of a image study, by month, by volume, or some other calculation, Brown says.
Poudre Valley Health System standardized its imaging platform and outsourced digital image storage and management to an outside provider. Three years ago, the nonprofit with four medical centers and hospitals in Colorado, Wyoming, and Nebraska, was preparing to upgrade its PACS, when it discovered its imaging storage needs "were exploding--there was no way we'd be able to pay for it," says Russ Branzell, CIO at Poudre.
In addition to the growing storage needs, Poudre Valley's doctors wanted access to images from multiple locations, not just while in the radiology offices. This meant expanding network bandwidth to enable multiple clinicians to be able to simultaneously access huge diagnostic-quality medical images.
To address these challenges, Poudre Valley decided to move its imaging system to an ASP model. It moved to a system where it now owns the imaging testing equipment as well as the images, but uses Philips to electronically send and store images.
Poudre Valley pays per click to access to an image, with each click representing access to a full medical imaging study that could include hundreds or thousands of slices depending on the exam, Branzell says.
The transfer of images to the new platform took 18 months, working 24 by 7, he says, and all the images needed to be available to the doctors during the transition.
Had Poudre Valley not moved to the ASP model, it would have had to double its imaging staff from four to eight to manage the systems. Instead, its staff now spends more time working with the clinicians, rather than tending the backend needs of the systems. Branzell estimates the ASP model is saving the company $1 million to $2 million a year.
"All our images are managed by one system, there's no longer a need for doctors to use different systems side by side," he says. In addition, all imaging reports feed into a patient's EMR, so doctors also have easy and secure access to those records while viewing images, he says.
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