Hong Kong achieves nationwide image distribution

The Hong Kong Hospital Authority, which manages all 43 public hospitals in the region, has enabled widespread image distribution through the integration of PACS into its electronic medical record.

"Technically, Hong Kong is not a country but a 'special administrative region.' But for all intents and purposes we are providing nationwide image distribution," said Dr. Ngai-Tseung Cheung of the Health Informatics Section of the Hong Kong Hospital Authority.

Cheung said the hospital authority took a budget approach that leverages the existing infrastructure but still provides many PACS benefits, particularly timely delivery of radiology images to clinicians through an integrated information system called the Clinical Management System. The system includes a territory-wide longitudinal electronic patient record (Comput Med Imaging Graph 2005;29(2-3):137-142).

Image integration into the electronic patient record is achieved by sending the completed images from the local PACS to the archive and then providing a link from the patient record directly to the image, Cheung said. When a user clicks on an image icon in the patient record, the image viewer is launched, and the appropriate study is loaded.

All hospitals are connected over a wide area network by high-speed leased lines with bandwidths ranging from 50 Mbps for major acute facilities to 2 Mbps for smaller institutions.

The electronic image distribution project attempts to leverage the extensive clinical information infrastructure already in place. It includes nearly 10,000 clinical workstations deployed throughout the hospital authority.

Cheung cited several differences between this project and a full corporate-wide PACS implementation:

• This is not a filmless project. The use of lossy compression greatly reduces the demand on storage and network bandwidth (and thus costs) but means that film will still have to be printed. Lossy images can serve only as a reference.

• This project will use the existing clinical workstations, which are generally 15-inch LCD or CRT monitors. Not only does this low monitor quality preclude diagnostic-grade image reading, but the small size also makes intensive image viewing and manipulation impractical.

• There will be no attempt to build sufficient resilience into the system to achieve the 99.999% reliability that is commonly preferred for PACS implementations.

"These three factors greatly reduce the cost and complexity of the project and enable us to provide corporate-wide image delivery for a fraction of the cost of a full PACS," he said.