Picture Archiving and Communication Systems

This chapter described the major system components and technologies related to picture archiving and communication systems (PACS) used in medical imaging. First a definition of PACS is provided followed by a brief description of the major components of a PACS. Several definitions have been cited in the chapter. One such definition is that PACS is fundamentally a highly sophisticated storage system that stores data and images from the image acquisition equipment and uses computer networks and application software not only to display images for viewing and interpretation but to transmit the data and images to remote locations, and as a result, PACS has become an enterprise image management system. Major components include image acquisition modalities, computer networks, the PACS main computer, image storage characteristics, image compression, display and analysis workstations, the radiology information system (RIS) and the PACS broker, and finally the web server. PACS is also characterized by the use of two communication standards, Digital Imaging and Communications in Medicine (DICOM®) and Health Level-7 (HL-7). While HL-7 deals with the flow of textual information between the hospital information system (HIS) and the RIS and other information systems in the hospital, DICOM® deals primarily with the exchange of images in the radiology department and facilitates communication among manufacturer-specific imaging equipment.