field digital mammography (ffdm) has taken a similar approach, largely because of the large image size, highly specialized reading workflow and display requirements, and intervention by regulators. the rapid deployment of ffdm in the us following the dmist study has led to the integration of digital mammography and pacs becoming more commonplace. all pacs, whether they span the entire enterprise or are localized within a department, should also interface with existing hospital information systems: hospital information system (his) and radiology information system (ris). there are several data flowing into pacs as inputs for next procedures and back to his as results corresponding inputs: in: patient identification and orders for examination. these data are sent from his to ris via integration interface, in most of hospital, via hl7 protocol. patient id and orders will be sent to modality (ct,mr,etc) via dicom protocol (worklist). images will be created after images scanning and then forwarded to pacs server. diagnosis report is created based on the images retrieved for presenting from pacs server by physician/radiologist and then saved to ris system. out: diagnosis report and images created accordingly. diagnosis report is sent back to his via hl7 usually and images are sent back to his via dicom usually if there is a dicom viewer integrated with his in hospitals (in most of cases, clinical physician gets reminder of diagnosis report coming and then queries images from pacs server). interfacing between multiple systems provides a more consistent and more reliable dataset: less risk of entering an incorrect patient id for a study – modalities that support dicom worklists can retrieve identifying patient information (patient name, patient number, accession number) for upcoming cases and present that to the technologist, preventing data entry errors during acquisition. once the acquisition is complete, the pacs can compare the embedded image data with a list of scheduled studies from ris, and can flag a warning if the image data does not match a scheduled study. data saved in the pacs can be tagged with unique patient identifiers (such as a social security number or nhs number) obtained from his. providing a robust method of merging datasets from multiple hospitals, even where the different centers use different id systems internally. an interface can also improve workflow patterns: when a study has been reported by a radiologist the pacs can mark it as read. this avoids needless double-reading. the report can be attached to the images and be viewable via a single interface. improved use of online storage and nearline storage in the image archive. the pacs can obtain lists of appointments and admissions in advance, allowing images to be pre-fetched from off-line storage or near-line storage onto online disk storage. recognition of the importance of integration has led a number of suppliers to develop fully integrated ris/pacs. these may offer a number of advanced features: dictation of reports can be integrated into a single system. integrated speech-to-text voice recognition software may be used to create and upload a report to the patient's chart within minutes of the patient's scan, or the reporting physician may dictate their findings into a phone system or voice recorder. that recording may be automatically sent to a transcript writer's workstation for typing, but it can also be made available for access by physicians, avoiding typing delays for urgent results, or retained in case of typing error. provides a single tool for quality control and audit purposes. rejected images can be tagged, allowing later analysis (as may be required under radiation protection legislation). workloads and turn-around time can be reported automatically for management purposes. acceptance testing the pacs installation process is complicated requiring time, resources, planning, and testing. installation is not complete until the acceptance test is passed. acceptance testing of a new installation is a vital step to assure user compliance, functionality, and especially clinical safety. take for example the therac-25, a radiation medical device involved in accidents in which patients were given massive overdoses of radiation, due to unverified software control. the acceptance test determines whether the pacs is ready for clinical use and marks the warranty timeline while serving as a payment milestone. the test process varies in time requirements depending on facility size but contract condition of 30-day time limit is not unusual. it requires detailed planning and development of testing criteria prior to writing the contract. it is a joint process requiring defined test protocols and benchmarks. testing uncovers deficiencies. a study determined that the most frequently cited deficiencies were the most costly components. failures ranked from most-to-least common are: workstation; his/ris/acs broker interfaces; ris; computer monitors; web-based image distribution system; modality interfaces; archive devices; maintenance; training; network; dicom; teleradiology; security; film digitizer. history one of the first basic pacs was created in 1972 by dr richard j. steckel.: 6 the principles of pacs were first discussed at meetings of radiologists in 1982. various people are credited with the coinage of the term pacs. cardiovascular radiologist dr andre duerinckx reported in 1983 that he had first used the term in 1981.: 9–18 dr samuel dwyer, though, credits dr judith m. prewitt for introducing the term.: 2–9 dr harold glass, a medical physicist working in london in the early 1990s secured uk government funding and managed the project over many years which transformed hammersmith hospital in london as the first filmless hospital in the united kingdom.: 469–478 dr glass died a few months after the project came live but is credited with being one of the pioneers of pacs. the first large-scale pacs installation was in 1982 at the university of kansas, kansas city. this first installation became more of a teaching experience of what not to do rather than what to do in a pacs installation. regulatory concerns in the us pacs are classified as medical devices, and hence if for sale are regulated by the usfda. in general they are subject to class 2 controls and hence require a 510(k), though individual pacs components may be subject to less stringent general controls. some specific applications, such as the use for primary mammography interpretation, are additionally regulated within the scope of the mammography quality standards act. the society for imaging informatics in medicine (siim) is the worldwide professional and trade organization that provides an annual meeting and a peer-reviewed journal to promote research and education about pacs and related digital topics.