For many medical institutions, the expense and management burdens of storing the big files created by picture archiving and communications systems (PACS) are fast growing beyond control. In
Outsourcing providers range from the large, such as Iron Mountain Inc., to the small, such as NCD Medical Corp., which serves medical institutions in Ohio. Whatever their size, PACS and the hospitals that use them have a unique set of needs: plenty of storage capacity for lots of large images, redundancy so uptime is guaranteed and images are not lost in case of disaster, intelligent archiving that saves images to comply with regulations, and fast retrieval of images when life and death hang in the balance.
"When you're loading an image off tape, five to seven minutes, even if the image is in the library, [is] just not acceptable," said Joe Granneman, chief technology officer at Rockford Health System in Rockford, Ill.
Despite its low cost, tape's often lengthy retrieval time and tendency to degrade pushed Granneman to get rid of Rockford Health's local tape storage and replace it with Iron Mountain's disk-based remote PACS storage service. Storing all image data on-site was ruled out because of disk and administrative costs, he said.
The Iron Mountain service includes an on-premises gateway that can store a large number of images in cache memory. The system automatically decides which images need to be cached for fast response. Even when images must be retrieved from Iron Mountain's remote storage locations, the response time is still considerably faster than local tape, Granneman said.
Rockford Health, which uses McKesson Corp.'s PACS, has 1.5 terabytes (TB) of cache storage on its Iron Mountain gateway, according to Granneman. For tier-one PACS image storage, Rockford Health maintains 7 TB of disk storage on its premises.
The move from tape to disk and a hosted service took some adjustment. "I manage it -- I'm responsible for it. At first, I was disconcerted that I was storing data across the country," Granneman said. So far, however, the change has been uneventful. Rockford Health began copying its tape image archive to Iron Mountain's service in October, and the process should be complete by mid-2010, according to Granneman.
On-site vs. off-site PACS image storage
Sending all images to a distant location is not for everyone. Like Rockford Health, HealthAlliance Hospital, with locations in Fitchburg, Mass., and Leominster, Mass., is storing its image files on disk rather than tape. But the hospital is keeping all its image data on-site in redundant storage area networks (SANs) built using IBM's Grid Medical Archive Solution (GMAS) storage with Siemens Healthcare's MagicWeb PACS. "It's all digital, all stored on GMAS. It just works," said Rick Mohnk, vice president and chief information officer at HealthAlliance, which is a member of the UMass Memorial Health Care hospital system.
When you're loading an image off tape, five to seven minutes, even if the image is in the library, [is] just not acceptable.
Joe Granneman, chief technology officer, Rockford Health System
Mohnk operates two redundant SANs in different parts of HealthAlliance's Leominster building, and is confident that the grid architecture of GMAS will be able to withstand any foreseeable disruptions. During a recent upgrade, his staff intentionally broke parts of the grid to install new systems. End users saw no difference in uptime, he said.
"We did a study of how much off-site data centers are used. Other than a hurricane, there weren't many examples of it. I don't anticipate a hurricane hitting Leominster [which is more than 40 miles inland]," Mohnk said. "One copy in one part of the building -- another in another part of the building. Unless the physical structure of the building is gone, what is going to happen?"
Keeping a local focus on PACS storage
NCD, in Eastlake, Ohio, offers a complete PACS, including both primary and secondary storage. As with Iron Mountain's service, all data is stored on disk rather than tape. The eWIX mini-PACS service is geared to medical institutions that want to avoid the cost and management headache of running an on-premises system.
NCD Medical runs a primary data center in Eastlake, Ohio, where two copies of each image are stored. A backup image is stored at a facility in nearby Columbus.
"At night we download to Columbus, so there are three sets of data at all times," said Chuck Patti, CEO of NCD Medical. For security, the image data is encrypted in storage and in transport. NCD charges a monthly fee based on the number of studies a client stores. A study consists of a series of images, and can include multiple modalities, such as X-rays and CT scans.
HIPAA, other mandates present unique PACS storage needs
Medical images are subject to various legal and regulatory retention mandates, and storage service providers must take those requirements into account. For example, images pertaining to new births must be kept for at least 21 years. Images relating to workers' compensation claims must be stored for varying amounts of time, depending on the level of the claim.
In addition, the Health Insurance Portability and Accountability Act of 1996 (HIPAA) requires that personal data be protected through three types of safeguards -- administrative, technical and procedural. Iron Mountain's PACS storage service is a type of technical safeguard, Granneman said.
HIPAA also mandates that outdated files on tape be disposed of in a way that does not jeopardize confidentiality. The move to all-disk storage obviates that requirement. Through Iron Mountain's service, Granneman is able to maintain confidentiality by keeping each patient's data in different storage pools. In addition, access to the image archive is protected by public key infrastructure technology.
Stan Gibson is a Boston-based contributing writer. Let us know what you think about the story; email firstname.lastname@example.org.
This was first published in January 2010