A picture archival communication system combines hierarchical storage management and high-speed data-management software.
BY STEVE REGENOLD
In the late 1990s, the University of Utah's radiology department began to take notice of the escalating storage costs and lack of easy access to its archive of X-rays and radiology images. Because of ever-increasing archive capacities, these inconveniences threatened to become real problems if not addressed. This concern prompted the radiology department to start looking at a digital imaging and storage alternative to its existing system.
When dealing with physical film, the hospital had to manage an extensive system incorporating couriers and multiple storage facilities. Recent radiology films were kept on-site at the hospital but still required physical transport to be accessed by any of the university's sister clinics. Older films were moved off-site and required courier delivery when a doctor needed to view a patient's old records.
To improve these delivery times and create a system that could be easily accessed from any of the university's sister clinics, the radiology department decided to begin implementation of a full-scale picture archival communication system (PACS) network. By converting traditional X-ray and radiology film to digital images, the university was able to put patients' medical images onto a network accessible from numerous sites at the university and its affiliated clinics. This system, which replaces film and lightboards with digital images displayed on special viewing stations, allows the university to save substantial administrative costs while significantly speeding up file access times. In addition, the clinics affiliated with the university have easy access to the cen-tralized image archive via a high-speed network.
Doctors no longer have to sort through physical film images or wait for important files to be delivered. When a patient needs care, the PACS network provides an on-line real-time system capable of fast access and retrieval as well as the safe storage of the irreplaceable radiology files.
University of Utah's PACS network provides an online real-time system capable of fast access to and retrieval of medical images.
With a healthcare network encompassing a hospital and nine clinics, the University of Utah's PACS network is one of the largest in the state. Laying the initial infrastructure, Matt Dewey, director of IS in the department of radiology, worked with his small staff to hook up 400 users to the PACS network. Multiple diagnostic viewing stations were installed throughout the hospitals and clinics, and a Web server was set up to give users Internet access to the bank of image files. In total, the PACS network presently supports files from more than 250,000 individual studies.
In a PACS network this expansive, substantial data storage issues are inherent. With nearly six million individual files, the radiology department's IS staff must organize, manage, and archive more than a dozen terabytes of crucial medical data. Not only must this data be instantly accessible to the university's doctors, but these CAT-scans, MRIs, and X-rays are regulated by the Federal Food and Drug Administration (FDA) and must be permanently archived for seven or more years.
To handle these daunting tasks, the university contracted Marconi Medical Systems, a Pittsburgh, PA-based communications and IT company. Working with StorageTek, Marconi decided to implement an advanced hierarchical storage management (HSM) setup. In this configuration, the files are managed on a two-tiered setup using both traditional hard disk RAID storage and a StorageTek Timber Wolf 9840 tape library. With the help of a file-management software program, the HSM system manages the university's files by logically organizing each file according to its importance. Frequently accessed files, for example, are stored on the fast hard disk cache while older, rarely used files are migrated to the 9840 tape archive. When correctly configured, an HSM setup lets systems administrators manage data cost-effectively and efficiently.
Marconi and StorageTek began creating the HSM system by installing the tape library and 2TB of online hard disk RAID. A Sun 5000 server running Solaris 2.5.1 was integrated to control the system. This substantial archive, called the Marconi IntelliStore, was set to store up to 22TB of data. Initially, a basic HSM software program was used to manage the system.
Before completing the Marconi PACS network, the IS department realized that a bottleneck was being caused by the old data-management software. The software was adequate for most functions but slow and cumbersome when working with advanced HSM features. Recognizing this problem, Marconi installed a data storage management program from LSC Inc. (which was recently acquired by Sun). Called SAM-FS, the program allowed the IS department to efficiently store huge volumes of data while automatically migrating the radiology files through the HSM system and into the 9840 tape archive.
"SAM-FS excels where our old data-management software simply bottlenecked," says Dewey. "By intelligently moving data between our online disk cache and the 9840 tape archive library, doctors are guaranteed efficient access to the important radiology files."
In addition to this quick access, the HSM setup provides redundant protection for the critical medical data. By creating multiple copies of the files, the data is archived across many different pieces of media, ensuring safe files for the time periods required by the FDA. All of these functions are done transparently, according to pre-set parameters.
"We're working with precious medical data and cannot allow for any network downtime," Dewey explains. "If there are any problems with the system, SAM-FS's internal diagnostic tools allow us to take a virtual 'snapshot' of the program, which can then be analyzed to determine the fix."
With SAM-FS in place, the hospital's HSM system was ready to manage the complex data of the PACS network. In total, the system will eventually support the files from 65,000 patients and more than 250,000 individual files-or approximately 22TB of data.
This system allows the university to save substantial administrative costs while significantly speeding up file-access times. In addition, the clinics affiliated with the university have easy access to the centralized image archive via a high-speed network.
When a patient is in need of care, the PACS network provides an online real-time system capable of fast access and retrieval as well as safe storage of the irreplaceable radiology files.
"I can't say that any one component has literally saved lives, but the overall improvements of this network have substantially increased the efficiency by which doctors can access files and diagnose patients' problems," says Dewey.
Steve Regenold is a freelance writer in Minneapolis, MN.