Through the Thames Valley Hospital Digital Imaging Network project, eight Southwestern Ontario hospitals and six family medical centers are now linked by a single picture archiving and communication system (PACS). The hospitals include London Health Sciences Center, St. Joseph Health Care London, Alexandra Hospital, Four Counties Health Services, St. Thomas Elgin General Hospital, Strathroy Middlesex General Hospital, Tillsonburg District Memorial Hospital and Woodstock General Hospital.
The Digital Imaging Network project is funded by the Canada Health Infoway, a nationwide program that supports the development of electronic health information systems across the country.
PACS is a shared network of digitally stored medical images, where clinicians can access electronic diagnostic images simultaneously from their workstations through a virtual private network (VPN). One huge benefit from the system was that it eliminated the need for patients to travel to other hospitals for specialist consultation. A family physician can consult with a specialist from another hospital electronically by having access to a diagnostic image at the same time, said Diane Beattie, CIO for St. Joseph Health Care and London Health Sciences Center.
"From a health quality perspective, [some of the benefits] are around responsiveness," said Beattie. "In the London area, we actually have the lowest wait times for MRIs and CT scans across Ontario."
Doctors benefit from PACS as well by having the capability to remotely view medical images through VPN connection and provide diagnosis, Beattie said. "So if the doctor is on call, he doesn't need to get up in the middle of the night and come to the hospital."
St. Joseph Health Care in London, Ont., which was the first facility to deploy PACS in the fall of 2004, said its digital diagnostic imaging has become filmless and paperless. When clinicians were previously dealing with film-based medical images, various problems would arise, such as difficulty in tracking down films or films getting lost, which sometimes resulted in having to perform duplicate tests, explained Beattie.
The London Health Sciences Center claimed it has gained a savings of C$1.2 million (US$1.04 million) in film savings alone. By spring of 2005, all eight hospitals have deployed and were online with the Digital Imaging Network project, Beattie said.
PACS consists of a two-tiered storage system, according to Peter Gilbert, IT director for St. Joseph Health Care and London Health Sciences Center. At the top of the architecture is a 10-terabyte-array digital storage system that holds the more recent and relevant images, Gilbert said. The system is based on Hewlett Packard's (HP's) storage area network architecture.
"If an exam is taken within a year, then that image will be sitting in the first-tier storage," said Gilbert. The image is also replicated in the second-tier storage, which uses HP's Medical Archiving (HPMA) system.
The HPMA runs on HP's ProLiant servers with x86 processors and HP StorageWorks Modular Smart Arrays. HPMA has a dual function, said Gilbert. It serves as a backup in the event that the first storage layer becomes unavailable. The HPMA also serves as a long-term cache for older images capable of housing up to 60 terabytes of storage or five years worth of archiving capacity, he added.
Gilbert said second-tier storage systems were traditionally tape-based and less expensive. This type of architecture, however, presented certain difficulties in the healthcare sector, which often deals with emergency situations.
"Because of our business requirement of being able to see these images through a Canada-wide emergency record if we need to, the time required to go and actually locate a tape, put it in a drive, extract the image and present it back to the first tier (system) would take far too long," Gilbert explained.
HPMA, however, provided low-cost disks set up in a redundant array with extra built-in features like image error correction, the ability to shift images between two mirroring data centers for optimized data distribution, and the "optional license protection" that allows easy migration of data as the storage architecture changes, Gilbert said.
Images stored on the HPMA are also protected by digital signatures to prevent tampering, said David Mosher, business manager for healthcare at HP Canada.
"When you have a medical image, you want to make sure it's not altered once it's created, (hence) protecting the integrity of the data," Mosher said.
The Digital Imaging Network project also involved GE Healthcare, which provided the PACS technology, and Cerner Corp.'s Cerner Millennium platform.