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The development and acceptance of the digital communication in medicine (DICOM) standard has become a basic requirement for the implementation of electronic imaging in radiology. DICOM is now evolving to provide a standard for electronic communication between radiology and other parts of the hospital enterprise. In a completely integrated filmless radiology department, there are 3 core computer systems, the picture archiving and communication system (PACS), the hospital or radiology information system (HIS, RIS), and the acquisition modality. Ideally, each would have bidirectional communication with the other 2 systems. At a minimum, a PACS must be able to receive and acknowledge receipt of image and demographic data from the modalities. Similarly, the modalities must be able to send images and demographic data to the PACS. Now that basic DICOM communication protocols for query or retrieval, storage, and print classes have become established through both conformance statements and intervendor testing, there has been an increase in interest in enhancing the functionality of communication between the 3 computers. Historically, demographic data passed to the PACS have been generated manually at the modality despite the existence of the same data on the HIS or RIS. In more current sophisticated implementations, acquisition modalities are able to receive patient and study-related data from the HIS or RIS. DICOM Modality Worklist is the missing electronic link that transfers this critical information between the acquisition modalities and the HIS or RIS. This report describes the concepts, issues, and impact of DICOM Modality Worklist implementation in a PACS environment.

The interfacing of digital image acquisition modalities to the picture archiving and communication system (PACS) plays a major part in the conversion from a traditional film-based radiology practice to one that relies almost entirely on soft-copy reading. The Baltimore Veterans Affairs Medical Center (VAMC) is one of the first filmless hospitals in the world. Since 1993, it has used computed tomography (CT) scanners connected to a commercial PACS to provide digitized patient images for filmless reading. Over the years, the evolution of Digital Imaging and Communications in Medicine (DICOM) standards, advances in networking technologies, and enhancements in PACS and hospital information system (HIS) software have greatly improved this system’s robustness and patient/study identification accuracy. The result has been a major increase in productivity.

As radiology makes advances toward filmlessness, all of medicine is headed, just as rapidly, toward paperless transmission of patient information. While there are obvious advantages to this electronic approach, and several standards to conform to for the transmission of textual (Health Level 7 [HL-7]) and image (Digital Imaging and Communications in Medicine [DICOM]) data, it is the integration of these two data sets that is clinically essential and yet poorly defined. This report defines an approach for, and the successful implementation of, the integration of radiologic image data with textual data contained within the electronic patient record (EPR) through the use of standard internet protocols. Incorporation of medical images in the EPR has proven to be critical to the successful deployment of picture archiving and communications systems (PACS) and the reduction of film consumption at Massachusetts General Hospital (MGH). Since the installation of the first internet-based Image Data Repository (IDR) at MGH in 1995, the system has adequately served to meet the needs of clinical requests by both radiology-only browser users and users of the EPR. It has drastically reduced the need for film and provided concurrent display of images and text throughout the institution and beyond. *** DIRECT SUPPORT *** A00RM031 00009

The use of digitized histopathologic specimens (also known as whole-slide images (WSIs)) in clinical medicine requires compatibility with the Digital Imaging and Communications in Medicine (DICOM) standard. Unfortunately, WSIs usually exceed DICOM image object size limit, making it impossible to store and exchange them in a straightforward way. Moreover, transmitting the entire DICOM image for viewing is ineffective for WSIs. With the JPEG2000 Interactive Protocol (JPIP), WSIs can be linked with DICOM by transmitting image data over an auxiliary connection, apart from patient data. In this study, we explored the feasibility of using JPIP to link JPEG2000 WSIs with a DICOM-based Picture Archiving and Communications System (PACS). We first modified an open-source DICOM library by adding support for JPIP as described in the existing DICOM Supplement 106. Second, the modified library was used as a basis for a software package (JVSdicom), which provides a proof-of-concept for a DICOM client–server system that can transmit patient data, conventional DICOM imagery (e.g., radiological), and JPIP-linked JPEG2000 WSIs. The software package consists of a compression application (JVSdicom Compressor) for producing DICOM-compatible JPEG2000 WSIs, a DICOM PACS server application (JVSdicom Server), and a DICOM PACS client application (JVSdicom Workstation). JVSdicom is available for free from our Web site (http://jvsmicroscope.uta.fi/), which also features a public JVSdicom Server, containing example X-ray images and histopathology WSIs of breast cancer cases. The software developed indicates that JPEG2000 and JPIP provide a well-working solution for linking WSIs with DICOM, requiring only minor modifications to current DICOM standard specification.

The use of digitized histopathologic specimens (also known as whole-slide images (WSIs)) in clinical medicine requires compatibility with the Digital Imaging and Communications in Medicine (DICOM) standard. Unfortunately, WSIs usually exceed DICOM image object size limit, making it impossible to store and exchange them in a straightforward way. Moreover, transmitting the entire DICOM image for viewing is ineffective for WSIs. With the JPEG2000 Interactive Protocol (JPIP), WSIs can be linked with DICOM by transmitting image data over an auxiliary connection, apart from patient data. In this study, we explored the feasibility of using JPIP to link JPEG2000 WSIs with a DICOM-based Picture Archiving and Communications System (PACS). We first modified an open-source DICOM library by adding support for JPIP as described in the existing DICOM Supplement 106. Second, the modified library was used as a basis for a software package (JVSdicom), which provides a proof-of-concept for a DICOM client–server system that can transmit patient data, conventional DICOM imagery (e.g., radiological), and JPIP-linked JPEG2000 WSIs. The software package consists of a compression application (JVSdicom Compressor) for producing DICOM-compatible JPEG2000 WSIs, a DICOM PACS server application (JVSdicom Server), and a DICOM PACS client application (JVSdicom Workstation). JVSdicom is available for free from our Web site (http://jvsmicroscope.uta.fi/), which also features a public JVSdicom Server, containing example X-ray images and histopathology WSIs of breast cancer cases. The software developed indicates that JPEG2000 and JPIP provide a well-working solution for linking WSIs with DICOM, requiring only minor modifications to current DICOM standard specification.

The University of California at San Francisco (USCF) Department of Radiology currently has a clinically operational picture archiving and communication system (PACS) that is thirty-five percent filmless, with the goal of becoming seventy-five percent filmless within the year. The design and implementation of the clinical PACS has been a collaborative effort between an academic research laboratory and a commercial vendor partner. Images are digitally acquired from three computed radiography (CR) scanners, five computed tomography (CT) scanners, five magnetic resonance (MR) imagers, three digital fluoroscopic rooms, an ultrasound mini-PACS and a nuclear medicine mini-PACS. The DICOM (Digital Imaging and Communications in Medicine) standard communications protocol and image format is adhered to throughout the PACS. Images are archived in hierarchical staged fashion, on a RAID (redundant array of inexpensive disks) and on magneto-optical disk jukeboxes. The clinical PACS uses an object-oriented Oracle SQL (systems query language) database, and interfaces to the Radiology Information System using the HL7 (Health Languages 7) standard. Components are networked using a combination of switched and fast ethernet, and ATM (asynchronous transfer mode), all over fiber optics. The wide area network links six UCSF sites in San Francisco. A combination of high and medium resolution dual-monitor display stations have been placed throughout the Department of Radiology, the Emergency Department (ED) and Intensive Care Units (ICU). A continuing quality improvement (CQI) committee has been formed to facilitate the PACS installation and training, workflow modifications, quality assurance and clinical acceptance. This committee includes radiologists at all levels (resident, fellow, attending), radiology technologists, film library personnel, ED and ICU clinian end-users, and PACS team members. The CQI committee has proved vital in the creation of new management procedures, providing a means for user feedback and education, and contributing to the overall acceptance of, and user satisfaction with the system. Well developed CQI procedures have been essential to the successful clinical operation of the PACS as UCSF Radiology moves toward, a filmless department.

The transition to filmless radiology is a much more formidable task than making the request for proposal to purchase a (Picture Archiving and Communications System) PACS. The Department of Defense and the Veterans Administration have been pioneers in the transformation of medical diagnostic imaging to the electronic environment. Many civilian sites are expected to implement large-scale PACS in the next five to ten years. This presentation will relate the empirical insights gleaned at our institution from a large-scale PACS implementation. Our PACS integration was introduced into a fully operational department (not a new hospital) in which work flow had to continue with minimal impact. Impediments to user acceptance will be addressed. The critical components of this enormous task will be discussed. The topics covered during this session will include issues such as phased implementation, DICOM (digital imaging and communications in medicine) standard-based interaction of devices, hospital information system (HIS)/radiology information system (RIS) interface, user approval, networking, workstation deployment and backup procedures. The presentation will make specific suggestions regarding the implementation team, operating instructions, quality control (QC), training and education. the concept of identifying key functional areas is relevant to transitioning the facility to be entirely on line. Special attention must be paid to specific functional areas such as the operating rooms and trauma rooms where the clinical requirements may not match the PACS capabilities. The printing of films may be necessary for certain circumstances. The integration of teleradiology and remote clinics into a PACS is a salient topic with respect to the overall role of the radiologists providing rapid consultation. A Webbased server allows a clinician to review images and reports on a desk-top (personal) computer and thus reduce the number of dedicated PACS review workstations. This session will focus on effective strategies for a seamless transition. Critical issues involve maintaining a good working relationship with the vendor, cultivating personnel readiness and instituting well-defined support systems. Success depends on the ability to integrate the institutional directives, user expectations and available technologies. A team approach is mandatory for success.

The US Department of Veterans Affairs (VA) is using the Digital Imaging and Communications in Medicine (DICOM) standard to integrate image data objects from multiple systems for use across the healthcare enterprise. DICOM uses a structured representation of image data and a communication mechanism that allows the VA to easily acquire radiology images and store them directly into the online patient record. Images can then be displayed on low-cost clinician's workstations throughout the medical center. High-resolution diagnostic quality multi-monitor VistA workstations with specialized viewing software can be used for reading radiology images. Various image and study specific items from the DICOM data object are essential for the correct display of images. The VA's DICOM capabilities are now used to interface seven different commercial Picture Archiving and Communication Systems (PACS) and over twenty different radiology image acquisition modalities.

The US Department of Veterans Affairs (VA) is using the Digital Imaging and Communications in Medicine (DICOM) standard to integrate image data objects from multiple systems for use across the health care enterprise. DICOM uses a structured representation of image data and a communication mechanism that allows the VA to easily acquire images from multiple sources and store them directly into the online patient record. The VA can obtain both radiology and nonradiology images using DICOM, and can display them on low-cost clinican’s color workstations throughout the medical center. High-resolution gray-scale diagnostic-quality multimonitor workstations with specialized viewing software can be used for reading radiology images. The VA’s DICOM capabilities can interface six different commercial picture archiving and communication systems (PACS) and more than 20 different image acquisition modalities. The VA is advancing its use of DICOM beyond radiology. New color imaging applications for gastrointestinal endoscopy and ophthalmology using DICOM are under development. These are the first DICOM offerings for the vendors, who are planning to support the recently passed DICOM Visible Light and Structured Reporting service classes. Implementing these in VistA is a challenge because of the different workflow and software support for these disciplines within the VA hospital information system (HIS) environment.

Objective: To support clinically relevant indexing of biomedical images and image-related information based on the attributes of image acquisition procedures and the judgments (observations) expressed by observers in the process of image interpretation.

Design: The authors introduce the notion of “image acquisition context,” the set of attributes that describe image acquisition procedures, and present a standards-based strategy for utilizing the attributes of image acquisition context as indexing and retrieval keys for digital image libraries.

Methods: The authors' indexing strategy is based on an interdependent message/terminology architecture that combines the Digital Imaging and Communication in Medicine (DICOM) standard, the SNOMED (Systematized Nomenclature of Human and Veterinary Medicine) vocabulary, and the SNOMED DICOM microglossary. The SNOMED DICOM microglossary provides context-dependent mapping of terminology to DICOM data elements.

Results: The capability of embedding standard coded descriptors in DICOM image headers and image-interpretation reports improves the potential for selective retrieval of image-related information. This favorably affects information management in digital libraries.

Recently, the digital imaging and communications in medicine (DICOM) standard introduced rules for the encoding, transmission, and storage of the imaging diagnostic report. This medical document can be stored and communicated with the images in picture archiving and communication system (PACS). It is a structured document that contains text with links to other data such as images, waveforms, and spatial or temporal coordinates. Its structure, along with its wide use of coded information, enables the semantic understanding of the data that is essential for the Electronic Healthcare Record deployment. In this article, we present DICOM Structured Report (SR) and discuss its benefits. We show how SR enables efficient radiology workflow, improves patient care, optimizes reimbursement, and enhances the radiology ergonomic working conditions. As structured input significantly alters the interpretation process, understanding all its benefits is necessary to support the change.

All modalities in radiology practice have become digital, and therefore deal with DICOM images. Image files that are compliant with part 10 of the DICOM standard are generally referred to as “DICOM format files” or simply “DICOM files” and are represented as “.dcm.” DICOM differs from other image formats in that it groups information into data sets. A DICOM file consists of a header and image data sets packed into a single file. The information within the header is organized as a constant and standardized series of tags. By extracting data from these tags one can access important information regarding the patient demographics, study parameters, etc. In the interest of patient confidentiality, all information that can be used to identify the patient should be removed before DICOM images are transmitted over a network for educational or other purposes. In addition to the DICOM format, the radiologist routinely encounters images of several file formats such as JPEG, TIFF, GIF, and PNG. Each format has its own unique advantages and disadvantages, which must be taken into consideration when images are archived, used in teaching files, or submitted for publication. Knowledge about these formats and their attributes, such as image resolution, image compression, and image metadata, helps the radiologist in optimizing the archival, organization, and display of images. This article aims to increase the awareness among radiologists regarding DICOM and other image file formats encountered in clinical practice. It also suggests several tips and tricks that can be used by the radiologist so that the digital potential of these images can be fully utilized for maximization of workflow in the radiology practice.

A distributed design is the most cost-effective system for small- to medium-scale picture archiving and communications systems (PACS) implementations. However, the design presents an interesting challenge to developers and implementers: to make stored image data, distributed throughout the PACS network, appear to be centralized with a single access point for users. A key component for the distributed system is a central or master database, containing all the studies that have been scanned into the PACS. Each study includes a list of one or more locations for that particular dataset so that applications can easily find it. Non-Digital Imaging and Communications in Medicine (DICOM) clients, such as our worldwide web (WWW)-based PACS browser, query the master database directly to find the images, then jump to the most appropriate location via a distributed web-based viewing system. The Master Database Broker provides DICOM clients with the same functionality by translating DICOM queries to master database searches and distributing retrieval requests transparently to the appropriate source. The Broker also acts as a storage service class provider, allowing users to store selected image subsets and reformatted images with the original study, without having to know on which server the original data are stored.

The radiology information system (RIS) provides patient and examination information that is used in setting up and performing a radiologic procedure. In a digital imaging environment, information from the RIS can also be used to populate fields in the Digital Imaging and Communications in Medicine (DICOM) image header. Ideally, information from the RIS should be available at the modality at the time of the examination, and automatically be attached to the image in the appropriate DICOM fields before storage in the picture archiving and communications system (PACS). We have designed a highly integrated RIS interface for a digital radiography (DR) system. This interface employs browser technology to make RIS information conveniently available at the modality, and DICOM modality performed procedure step (MPPS) for RIS/DR information exchange. A novel feature of our approach is that a single display screen at the modality is used to alternatively display either the modality control window or the RIS window. Full access to RIS capabilities is available at the modality, including worklists and prior reports.

Background

Ultrasound scanning uses the medical imaging format, DICOM, for electronically storing the images and data associated with a particular scan. Large health care facilities typically use a picture archiving and communication system (PACS) for storing and retrieving such images. However, these systems are usually not suitable for managing large collections of anonymized ultrasound images gathered during a clinical screening trial.

Results

We have developed a system enabling the accurate archiving and management of ultrasound images gathered during a clinical screening trial. It is based upon a Windows application utilizing an open-source DICOM image viewer and a relational database. The system automates the bulk import of DICOM files from removable media by cross-validating the patient information against an external database, anonymizing the data as well as the image, and then storing the contents of the file as a field in a database record. These image records may then be retrieved from the database and presented in a tree-view control so that the user can select particular images for display in a DICOM viewer or export them to external media.

Conclusion

This system provides error-free automation of ultrasound image archiving and management, suitable for use in a clinical trial. An open-source project has been established to promote continued development of the system.

The integration of images with existing and new health care information systems poses a number of challenges in a multi-facility network: image distribution to clinicians; making DICOM image headers consistent across information systems; and integration of teleradiology into PACS. A novel, Web-based enterprise PACS architecture introduced at Massachusetts General Hospital provides a solution. Four AMICAS Web/Intranet Image Servers were installed as the default DICOM destination of 10 digital modalities. A fifth AMICAS receives teleradiology studies via the Internet. Each AMICAS includes: a Java-based interface to the IDXrad radiology information system (RIS), a DICOM autorouter to tape-library archives and to the Agfa PACS, a wavelet image compressor/decompressor that preserves compatibility with DICOM workstations, a Web server to distribute images throughout the enterprise, and an extensible interface which permits links between other HIS and AMICAS. Using wavelet compression and Internet standards as its native formats, AMICAS creates a bridge to the DICOM networks of remote imaging centers via the Internet. This teleradiology capability is integrated into the DICOM network and the PACS thereby eliminating the need for special teleradiology workstations. AMICAS has been installed at MGH since March of 1997. During that time, it has been a reliable component of the evolving digital image distribution system. As a result, the recently renovated neurosurgical ICU will be filmless and use only AMICAS workstations for mission-critical patient care.

The Department of Defense issued a Request for Proposal (RFP) for its next generation Picture Archiving and Communications System in January of 1997. The RFP was titled Digital Imaging Network—Picture Archiving and Communications System (DIN-PACS). Benchmark testing of the proposed vendors' systems occurred during the summer of 1997. This article highlights the methods for test material and test system organization, the major areas tested, and conduct of actual testing. Department of Defense and contract personnel wrote test procedures for benchmark testing based on the important features of the DIN-PACS Request for Proposal. Identical testing was performed with each vendor's system. The Digital Imaging and Communications in Medicine (DICOM) standard images used for the Benchmark Testing included all modalities. The images were verified as being DICOM standard compliant by the Mallinckrodt Institute of Radiology, Electronic Radiology Laboratory. The Johns Hopkins University Applied Physics Laboratory prepared the Unix-based server for the DICOM images and operated it during testing. The server was loaded with the images and shipped to each vendor's facility for on-site testing. The Defense Supply Center, Philadelphia (DSCP), the Department of Defense agency managing the DIN-PACS contract, provided representatives at each vendor site to ensure all tests were performed equitably and without bias. Each vendor's system was evaluated in the following nine major areas: DICOM Compliance; System Storage and Archive of Images; Network Performance; Workstation Performance; Radiology Information System Performance; Composite Health Care System/ Health Level 7 communications standard Interface Performance; Teleradiology Performance; Quality Control; and Failover Functionality. These major sections were subdivided into workable test procedures and were then scored. A combined score for each section was compiled from this data. The names of the involved vendors and the scoring for each is contract sensitive and therefore can not be discussed. All of the vendors that underwent the benchmark testing did well. There was no one vendor that was markedly superior or inferior. There was a typical bell shaped curve of abilities. Each vendor had their own strong points and weaknesses. A standardized benchmark protocol and testing system for PACS architectures would be of great value to all agencies planning to purchase a PACS. This added information would assure the purchased system meets the needed functional requirements as outlined by the purchasers PACS Request for Proposal.

To facilitate the integration of digital radiography (DR) and legacy film/screen technology, we have devised a methodology for film digitization that optimizes workflow and integrates well with the picture archiving and communication system (PACS). This work was performed at Mercy Medical Center (Cedar Rapids, IA) using a film digitizer with built-in Digital Imaging and Communications in Medicine (DICOM) communication. The radiology department at Mercy has one DR system and three separate film/screen systems. The DR system software suite features DICOM Modality Worklist capability to provide complete radiology information system (RIS) integration functionality. This provides for patient demographic information to be automatically downloaded from the RIS worklist to populate the DICOM image header. Likewise, we have taken advantage of the film scanner’s DICOM capability to develop software linking it with the hospital RIS. This capability provides a worklist downloading functionality equivalent to that of the DR. Patient demographics can then be rapidly downloaded as each film is digitized. The worklist capability of the scanner is essential in several respects. First, it guarantees that patient demographic information is completely accurate and, therefore, that the digitized x-ray image will be merged with the correct patient file in the PACS. Additionally, high film scanner throughput is achieved, guaranteeing that all inpatient-digitized films are as readily available on the PACS as their DR image counterparts. The digitized images have proven to be of diagnostic quality on the typical 1K by IK PACS workstation. Also, as patients are admitted to the hospital, prior films from the radiology archive are digitized to form a readily available patient history for in-house physicians. Over time, we are building archival patient histories of soft-copy images that will enable increased availability of patient x-rays to both in-hospital and outside referring physicians, especially as more internet-viewing software becomes available to the out-of-hospital medical community. Finally, the results of this study show that high-throughput RIS integraton of film scanning equipment is a key component to making a graceful transition to the filmless hospital as more DR systems are installed.

Conquest Hospital was a UK regional development site for a pre-Digital Imaging and Communications in Medicine (DICOM) picture archiving and communication system (PACS). The initial system was installed in mid 1992. Identification has been made of data transfer, ergonomic and single point of failure issues in the original PACS, which was called “iLAN.” This has informed respecification of a DICOM/HTML PACS, the first stages of which have been hospital renetworking and installation of new DICOM 3.0 computed radiography/fluorography and computed tomography/magnetic resonance imaging segments. Final PACS elements are at contract stage. Plans are being completed for linkage of PACS to a clinical information system to create a comprehensive electronic patient record system.

Electronic archiving of radiology images over many years will require many terabytes of storage with a need for rapid retrieval of these images. As more large PACS installations are installed and implemented, a data crisis occurs. The ability to store this large amount of data using the traditional method of optical jukeboxes or online disk alone becomes an unworkable solution. The amount of floor space, number of optical jukeboxes, and off-line shelf storage required to store the images becomes unmanageable. With the recent advances in tape and tape drives, the use of tape for long term storage of PACS data has become the preferred alternative. A PACS system consisting of a centrally managed system of RAID disk, software and at the heart of the system, tape, presents a solution that for the first time solves the problems of multi-modality high end PACS, non-DICOM image, electronic medical record and ADT data storage. This paper will examine the installation of the University of Utah, Department of Radiology PACS system and the integration of automated tape archive. The tape archive is also capable of storing data other than traditional PACS data. The implementation of an automated data archive to serve the many other needs of a large hospital will also be discussed. This will include the integration of a filmless cardiology department and the backup/archival needs of a traditional MIS department. The need for high bandwidth to tape with a large RAID cache will be examined and how with an interface to a RIS pre-fetch engine, tape can be a superior solution to optical platters or other archival solutions. The data management software will be discussed in detail. The performance and cost of RAID disk cache and automated tape compared to a solution that includes optical will be examined.

Purpose

To develop a personal computer (PC)-based software package that allows portability of the electronic imaging record. To create custom software that enhances the transfer of images in two fashions. Firstly, to an end user, whether physician or patient, provide a browser capable of viewing digital images on a conventional personal computer. Second, to provide the ability to transfer the archived Digital Imaging and Communications in Medicine (DICOM) images to other institutional picture archiving and communications systems (PACS) through a transfer engine.Method/materials: Radiologic studies are provided on a CD-ROM. This CD-ROM contains a copy of the browser to view images, a DICOM-based engine to transfer images to the receiving institutional PACS, and copies of all pertinent imaging studies for the particular patient. The host computer system in an Intel based Pentium 90 MHz PC with Microsoft Windows 95 software (Microsoft Inc, Seattle, WA). The system has 48 MB of random access memory, a 3.0 GB hard disk, and a Smart and Friendly CD-R 2006 CD-ROM recorder (Smart and Friendly Inc, Chatsworth, CA).Results: Each CD-ROM disc can hold 640 MB of data. In our experience, this houses anywhere from, based on Table 1, 12 to 30 computed tomography (CT) examinations, 24 to 80 magnetic resonance (MR) examinations, 60 to 128 ultrasound examinations, 32 to 64 computed radiographic examinations, 80 digitized x-rays, or five digitized mammography examinations. We have been able to successfully transfer DICOM images from one DICOM-based PACS to another DICOM-based PACS. This is accomplished by inserting the created CD-ROM onto a CD drive attached to the receiving PACS and running the transfer engine application.Conclusions: Providing copies of radiologic studies performed to the patient is a necessity in every radiology department. Conventionally, film libraries have provided copies to the patient generating issues of cost of loss of film, as well as mailing costs. This software package saves costs and loss of studies, as well as improving patient care by enabling the patient to maintain an archive of their electronic imaging record.

This presentation describes our experience and lessons learned over the first 3 years of developing and operating a filmless picture archiving and communications system (PACS) for all computed tomography (CT), magnetic resonance (MR), ultrasound, and nuclear medicine studies in our hospital. The PACS conforms to the Digital Imaging and Communications in Medicine (DICOM) standard and includes a sophisticated Worldwide Web (WWW)-based interface to complement the regular DICOM services. The PACS has undergone many design modifications from its inception, which have addressed performance, functionality, support, and maintenance issues. The lessons we have learned through making these modifications are described here and may prove to be helpful to anyone planning to deploy a PACS of their own.

Collaborations in biomedical research and clinical studies require that data, software, and computational resources be shared between geographically distant institutions. In radiology, there is a related issue of sharing remote DICOM data over the Internet. This paper focuses on the problem of federating multiple image data resources such that clients can interact with them as if they are stored in a centralized PACS. We present a toolkit, called VirtualPACS, to support this functionality. Using the toolkit, users can perform standard DICOM operations (query, retrieve, and submit) across distributed image databases. The key features of the toolkit are: (1) VirtualPACS makes it easy to use existing DICOM client applications for data access; (2) it can easily be incorporated into an imaging workflow as a DICOM source; (3) using VirtualPACS, heterogeneous collections of DICOM sources are exposed to clients through a uniform interface and common data model; and (4) DICOM image databases without DICOM messaging can be accessed.

Online teaching files are an important source of educational and referential materials in the radiology community. The commonly used Digital Imaging and Communications in Medicine (DICOM) file format of the radiology community is not natively supported by common Web browsers. The ability of the Web server to convert and parse DICOM is important when the DICOM-converting tools are not available. In this paper, we describe our approach to develop a Web-based teaching file authoring tool. Our server is built using Apache Web server running on FreeBSD operating system. The dynamic page content is produced by Hypertext Preprocessor (PHP). Digital Imaging and Communications in Medicine images are converted by ImageMagick into Joint Photographic Experts Group (JPEG) format. Digital Imaging and Communications in Medicine attributes are parsed by dicom3tools and stored in PostgreSQL database. Using free software available from the Internet, we build a Web service that allows radiologists to create their own online teaching file cases with a common Web browser.

Texas Children’s Hospital is a pediatric tertiary care facility in the Texas Medical Center with a large-scale, Digital Imaging and Communications in Medicine (DICOM)-compliant picture archival and communications system (PACS) installation. As our PACS has grown from an ultrasound niche PACS into a full-scale, multimodality operation, assuring continuity of clinical operations has become the number one task of the PACS staff. As new equipment is acquired and incorporated into the PACS, workflow processes, responsibilities, and job descriptions must be revised to accommodate filmless operations. Round-the-clock clinical operations must be supported with round-the-clock service, including three shifts, weekends, and holidays. To avoid unnecessary interruptions in clinical service, this requirement includes properly trained operators and users, as well as service personnel. Redundancy is a cornerstone in assuring continuity of clinical operations. This includes all PACS components such as acquisition, network interfaces, gateways, archive, and display. Where redundancy is not feasible, spare parts must be readily available. The need for redundancy also includes trained personnel. Procedures for contingency operations in the event of equipment failures must be devised, documented, and rehearsed. Contingency operations might be required in the event of scheduled as well as unscheduled service events, power outages, network outages, or interruption of the radiology information system (RIS) interface. Methods must be developed and implemented for reporting and documenting problems. We have a Trouble Call service that records a voice message and automatically pages the PACS Console Operator on duty. We also have developed a Maintenance Module on our RIS system where service calls are recorded by technologists and service actions are recorded and monitored by PACS support personnel. In a filmless environment, responsibility for the delivery of images to the radiologist and referring physician must be accepted by each imaging supervisor. Thus, each supervisor must initiate processes to verify correct patient and examination identification and the correct count and routing of images with each examination.