Bush__The_Essential_Physics_for_Medical_Imaging - Biomedical ...

Picture Archiving and Communications SystemsA PACS consists of interfaces to imaging devices that produce digital images, possiblydevices to digitize film images, a digital archive to store the images, displayworkstations to permit physicians to view the images, and a computer network tolink them. There also must be a database program to track the locations of imagesand user software that allows interpreting physicians to select and manipulateimages. Links to other networks, such as the hospital information system (HIS) andradiology information system (RIS), are useful.PACS vary widely in size and in scope. A PACS may be devoted to only a singlemodality at a medical facility, such as a nuclear medicine department, the ultrasoundsection, a couple of cardiac catheterization laboratories, or the x-ray computedtomography (CT) and magnetic resonance imaging (MRI) facilities. In thiscase, the entire PACS may be connected by a single LAN. Such a small, singlemodalityPACS is sometimes called a mini-PACS (Fig. 17-3). On the other hand, aPACS may incorporate all imaging modalities in a system of several medical centersand affiliated clinics (Fig. 17-4). In addition, a PACS may permit images to beviewed only by interpreting physicians or it may make them available to the emergencydepartment, intensive care units, and attending physicians as well. In thesecases, the PACS is likely to exist on an extended LAN or on a WAN constructedfrom multiple LANs.StorageServerRadiologistviewingareaFIGURE 17-3. Mini-PACS. A mini-PACS is a picture archiving and communicationssystem serving a single modality, such as ultrasound, nuclear imaging,or computed tomography. Shown is an ultrasound mini-PACS that servesfour ultrasound scanners and is connected by a hub to a file server and severalradiologist workstations.