Cisco Wide Area Application Services Version 4.0 Optimizations for PACS and Digital Image Storage

HCOs use a picture archiving communication system (PACS) as the primary application to manage digital images. PACS is a combination of application, database management system (DBMS), Web servers, and storage media, as shown in Figure 1. Digital imaging services are expanding exponentially in the volume of patient encounters, the number of specialties that use the technology, and the number and size of images in a study, as shown in Table 1. The expansion of imaging services requires PACS and the supporting infrastructure to scale beyond radiology and across a much larger, more diverse and distributed environment.

Many remote clinics and sites have limited WAN connections for cost or availability reasons. These same clinics may need to transmit images acquired at their sites to the central archive for radiologist interpretation or other purposes. The WAN link is sized for normal transport demands and not designed to support delivery of large image files. Although this approach is cost-effective for most remote operations, it restricts communications and image delivery assurance. Image transport times across small WAN circuits can exceed Digital Imaging and Communications in Medicine (DICOM) latency requirements, thus causing timeouts or even failures. Even though image modality, PACS, and the network are all operating normally, the image is not delivered properly to PACS because of lowbandwidth, high-latency network conditions.