The US Department of Veterans Affairs (VA) is integrating imaging into the healthcare enterprise using the Digital Imaging and Communication in Medicine (DICOM) standard protocols. Image management is directly integrated into the VistA Hospital Information System (HIS) software and the clinical database. Radiology images are acquired via DICOM, and are stored directly in the HIS database. Images can 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. Two approaches are used to acquire and handle imags within the radiology department. Some sties have a commercial Picture Archiving and Communications System (PACS) interfaced to the VistA HIS, while other sites use the direct image acquisition and integrated diagnostic reading capabilities of VistA itself. A small set of DICOM services have been implemented by VistA to allow patient and study text data to be transmitted to image producing modalities and the commercial PACS, and to enable images and study data to be transferred back. The VistA DICOM capabilities are now used to interface seven different commercial PACS products and over twenty different radiology modalities. The communications capabilities of DICOM and the VA wide area network are begin used to support reading of radiology images form remote sites. DICOM has been the cornerstone in the ability to integrate imaging functionality into the Healthcare Enterprise. Because of its openness, it allows the integration of system component from commercial and non- commercial sources to work together to provide functional cost-effective solutions. As DICOM expands to non-radiology devices, integration must occur with the specialty information subsystems that handle orders and reports, their associated DICOM image capture systems, and the computer- based patient record. The mode and concepts of the DICOM standard can be extended to these other areas, but some adjustments may be required.

The ongoing integration of hospital information systems (HIS) continues. Data storage systems, data networks and computers improve, data bases grow and health-care applications increase. Some computer operating systems continue to evolve and some fade. Health care delivery now depends on this computer-assisted environment. The result is the critical harmonization of the various hospital information systems becomes increasingly difficult. The purpose of this paper is to present an architecture for HIS integration that is computer-language-neutral and computer- hardware-neutral for the informatics applications. The proposed architecture builds upon the work done at the University of Arizona on middleware, the work of the National Electrical Manufacturers Association, and the American College of Radiology. It is a fresh approach to allowing applications engineers to access medical data easily and thus concentrates on the application techniques in which they are expert without struggling with medical information syntaxes. The HIS can be modeled using a hierarchy of information sub-systems thus facilitating its understanding. The architecture includes the resulting information model along with a strict but intuitive application programming interface, managed by CORBA. The CORBA requirement facilitates interoperability. It should also reduce software and hardware development times.

Improved presentation of the results of Diagnostic Medical Procedures must improve the communication of relevant information to the requesting clinician and so should improve the quality of healthcare. Facilities are now available to enable the preparation of Multimedia Medical Reports. Conventional reports are frequently accompanied by relevant Procedure Products, such as images and curves. Benefit should be obtained if audible and visible annotation is included. Project Team 34 of CEN/TC251 Draft First Working Document provides an overview of the use of Health Care Multimedia Reports. The aim of this paper is to summarize the needs for the creation, modification and presentation of Multimedia Reports, to describe a specific generic data structure for Procedure Product data, to describe one possible model for the Multimedia Report record and to discus the requirements for Multimedia Report authoring tools and presentation systems.

A model encompassing both PACS and medical records domains is described, wherein the entire patient record is represented by a collection of discrete information objects. These information objects can be stored DICOM Information Object Definitions (IODs) and the proposed HL7 Patient Record Architecture documents are found to fit this model. Relevant aspects of the both the proposed DICOM Structured Reporting and HL7 Document Patient Record Architecture standards are reviewed. The mapping of DICOM IODs to HL7 PRA documents is considered, and found to be one-to-one for all the use cases considered.

The authors have developed a next generation PACS architecture. This PACS is based on DICOM, HL7 and other standards. The architecture is highly distributed and highly scalable, while allowing for high performance, significant workflow improvements and the minimization of network traffic. The possibility of interfacing to an existing HIS/RIS is allowed for in a fashion that addresses workflow issues, on a 'best effort' basis. THe integration of a commercial RIS into the PACS, so as to optimize workflow and minimize database proliferation, is allowed for. A cost- effective standard based distributed PACS can be built today. Such a system has numerous advantages over current non-distributed systems. These advantages include, improved network usage, improved workflow, true scalability without loss of investment and improved robustness, as there need be no single point of failure.

The purpose of this paper is to integrate multiple DICOM image webservers into the currently existing enterprises- wide web-browsable electronic medical record. Over the last six years the University of Washington has created a clinical data repository combining in a distributed relational database information from multiple departmental databases (MIND). A character cell-based view of this data called the Mini Medical Record (MMR) has been available for four years, MINDscape, unlike the text-based MMR. provides a platform independent, dynamic, web browser view of the MIND database that can be easily linked with medical knowledge resources on the network, like PubMed and the Federated Drug Reference. There are over 10,000 MINDscape user accounts at the University of Washington Academic Medical Centers. The weekday average number of hits to MINDscape is 35,302 and weekday average number of individual users is 1252. DICOM images from multiple webservers are now being viewed through the MINDscape electronic medical record.

Currently, various data formats are widely used for medical imags, e.g. DICOM for exchange through network and storage media, and INTERFILE for image exchange in nuclear medicine. These formats are only able partly to solve problems arising in accessing and handling imags. To solve such problems, an ontology dedicated to the description of data and knowledge involved in the handling and the management of medical images has been designed. The ontology offers a semantic frame of reference to which manipulation tools can refer. It considers various point of view on the data, related to the context of production, the content,and the data quality. It supports several levels of abstraction, going from a declarative level related to the examination type to the implementation level. Moreover, the ontology provides mechanisms allowing the creation and the description of new entities. It can, thus, act as an intermediate language ensuring accurate reuse of the entities. This paper, which presents work in progress, is focused on the description of the ontology and points out how to use it for the description of and the access to DICOM or INTERFILE entities, and for the extension of the DICOM or INTERFILE dictionaries, by adding new entities, in order to describe complex relationships between images.

To ensure the acceptance of telemedical applications several obstacles must be overcome: the transfer of huge amounts of data over heterogeneous hard- and software platforms must be optimized; extended data post-processing is often required; and data security must be taken into consideration; post- processing based on secured data exchange must retain the relationship between original and post-processed images. To analyze and solve these problems, applications of distributed medical services were integrated. Data transfer and management was based on the Digital Imaging and Communications (DICOM) standard. To account for platform- independence of remote users, a novel DICOM server and viewer as implemented in JAVA. Different DICOM-conform data security concepts were analyzed. Encryption of the complete data stream using secure socket layers as well as a partial encryption concepts were tested. The best result was attained by a DICOM-conform encryption of patient-relevant data. The implementation medical services, which used newly develop techniques of magnetic resonance imaging, allowed a much earlier diagnosis of the human brain infarct. The integrated data security enabled remote segmentation within the unsecured internet, followed by storing the data back into the secured network.

The introduction of new digital detector technology for projection radiography created an opportunity to revisit the support for x-ray images in the DICOM standard. A new family of digital x-ray objects has been developed with greater emphasis on the productivity and workflow requirements of PACS and soft copy reading on workstations. The use of these DX objects present new design challenges for acquisition and display systems.

The selection criteria for the archive were based on the objectives of the Medical Information, Communication and Archive System (MICAS), a multi-vendor incremental approach to PACS. These objectives include interoperability between all components, seamless integration of the Radiology Information System (RIS) with MICAS and eventually other hospital databases, all components must demonstrate DICOM compliance prior to acceptance and automated workflow that can be programmed to meet changes in the healthcare environment. The long-term multi-modality archive is being implemented in 3 or more phases with the first phase designed to provide a 12 to 18 month storage solution. This decision was made because the cost per GB of storage is rapidly decreasing and the speed at which data can be retrieved is increasing with time. The open-solution selected allows incorporation of leading edge, 'best of breed' hardware and software and provides maximum jukeboxes, provides maximum flexibility of workflow both within and outside of radiology. The selected solution is media independent, supports multiple jukeboxes, provides expandable storage capacity and will provide redundancy and fault tolerance at minimal cost. Some of the required attributes of the archive include scalable archive strategy, virtual image database with global query and object-oriented database. The selection process took approximately 10 months with Cemax-Icon being the vendor selected. Prior to signing a purchase order, Cemax-Icon performed a site survey, agreed upon the acceptance test protocol and provided a written guarantee of connectivity between their archive and the imaging modalities and other MICAS components.

The operative pictures are important medical resources. But currently, the operational record doesn't include the operative pictures. The surgeons usually keep the pictures by themselves. So the operative pictures are occasionally lost or destroyed. It prevents exploration of the great education and research potential of operative pictures. This research developed the methods for operative pictures acquisition, processing, storage, and retrieval. Especially, the study employed an algorithm for picture retrieval by its content. This special retrieval facility offers querying by sample pictures, and it conquers the limitation of user experience and training. This approach also developed an operational record database for accommodating picture relational information. It provides the complete information about the operative pictures. So the query result in snot just only the pictures and surgeon annotations, it also provides all relational information of the patients. This facilitates the database utilization in other departments, not just only serving for surgery.

As PACS gain greater acceptance and use in medical facilities the question of life cycle management must be addressed in terms that relate to the common business practices for medical information system and medical devices. The issues in life cycle management of such a system are relatively new to the industry. Increased use of PACS within the medical community requires that standardized life cycle management practices by developed and implemented. This paper develops a new of life cycle issues as cyclic and related events that are not only manageable, but also predictable in terms, of, frequency, duration data content, data exchange, potential outcomes, staffing requirement, documentation, and staff interaction. This view is presented as a continuum that begins at the acceptance testing of a PACS and continues throughout its life cycle. The continuum incorporates the required relationship between quality control testing and maintenance actions during warranty period and the maintenance years. Interrelated cyclic events are described that bind these processes together and provide a basis for long-term proactive management of PACS in a medical environment.

This paper introduces a summary of the standard draft of ISCL 1.00 which will be published by MEDIS-DC officially. ISCL is abbreviation of Integrated Secure Communication Layer Protocols for Secure Medical Image Management Systems. ISCL is a security layer which manages security function between presentation layer and TCP/IP layer. ISCL mechanism depends on basic function of a smart IC card and symmetric secret key mechanism. A symmetry key for each session is made by internal authentication function of a smart IC card with a random number. ISCL has three functions which assure authentication, confidently and integrity. Entity authentication process is done through 3 path 4 way method using functions of internal authentication and external authentication of a smart iC card. Confidentially algorithm and MAC algorithm for integrity are able to be selected. ISCL protocols are communicating through Message Block which consists of Message Header and Message Data. ISCL protocols are evaluating by applying to regional collaboration system for image diagnosis, and On-line Secure Electronic Storage system for medical images. These projects are supported by Medical Information System Development Center. These project shows ISCL is useful to keep security.

In medical image processing original image data on archive servers may absolutely not be modified directly. On the other hand, images from read-only devices like CD-ROM cannot be changed and saved on the same storage medium. In both cases the modified data have to be stored as a second version and large amounts of storage volume are needed. We avoid these problems by using a program which records only each transaction prescribed to images. Each transaction is stored and used for further utilization and for renewed submission of the modified data. Conventionally, every time an image is viewed or printed, the modified version has to be saved in addition to the recorded data, either automatically or by the user. Compared to these approaches which not only squander storage space but area also time consuming our program has the following and advantages: First, the original image data which may not be modified are protected against manipulation. Second, small amounts of storage volume and network range are needed. Third, approved image operations can be automated by macros derived from transaction recordings. Finally, operations on the original data can always be controlled and traced back. As the handling of images gets easier with this concept, security for original image data is granted.

Image authenticity and integrity is an important issue in a telemammography system. We present an algorithm which can embed encrypted image and patient information into an image. The embedded information can be extracted and decrypted by the receiving site to verify the patient identification and confirm image authenticity and integrity.

This paper addresses the challenges that the clinical information system manager faces when selecting a core network technology to meet the ever increasing demand for bandwidth and efficiency in the digital radiology environment. Important metrics include network performance, reliability, cost, and computability with existing infrastructure. This work presents and compares the salient features of the two predominant high-speed radiology network solutions; asynchronous transfer mode and gigabit Ethernet. Its goal is to enable the information system manager to made informed decisions that are in the best interest of the radiology department. Since these two technologies are more complementary than competitive, a perspective of the benefits and risks of selecting each technology is presented. Recommendations are then made based upon the criteria presented from the overall clinical task.

In July 1996 the Arizona Telemedicine Program (ATP) was initiated by the state legislature in recognition of the needs of under-served populations in the state. Two important goals are: establish a statewide telemedicine network infrastructure; and use that infrastructure as a test bed to evaluate the effectiveness of state-of-the-art telemedicine services. These two goals exist in the context of an integrated, multidisciplinary telemedicine program. It is necessary to accommodate distinct levels of connectivity for sites depending on their association with the program and the corresponding level of services to be provided. For remote client sites requiring the highest level of service were selected the use of dedicated T1 circuits. At these sites the capabilities provided include: PC based store-and- forward services; point-to-point interactive real-time video interactions for clinical encounters; and multi-point interactive real-time video interactions for support groups and educational activities. For sites funded for lower levels of service we selected simple dial-up telephone based communications to support store-and-forward activities and inexpensive telephone based video conferencing equipment for administrative interactions. At the service sites distributed within the Arizona Health Sciences Center (AHSC) we selected standard LAN technology for store-and-forward applications and T1 based services for interactive video. To integrate these services we selected the Asynchronous Transfer Mode (ATM) protocol, integrated with the LAN environment within the AHSC. The integrated telemedicine network supports eight client sites and two service sites with T1-based ATM and four sites with dial-up lines. At the AHSC, ATM and LAN infrastructure is distributed to several clinical areas, allowing physicians to support telemedicine activities where they normally work. Between July 1997 and Jan 1999 over 2000 telemedicine sessions have been performed, nearly 50 percent of which are teleradiology consults. The use of T1-based ATM has facilitated the development of a wide-area infrastructure that has been easily integrated with LAN and dial-up technology to provide the foundation for diverse telemedicine services.

Fiber channel is a new data transfer interface technology that provides high-bandwidth data communication between computer systems and peripheral storage devices. We are implementing a digital mammography PACS module with fiber channel connectivity that facilitates the storage and communication of images between the individual PACS components.

Designing an image archive and retrieval system that supports multiple users with many different requirements and patterns of use without compromising the performance and functionality required by diagnostic radiology is an intellectual and technical challenge. A diagnostic archive, optimized for performance when retrieving diagnostic images for radiologists needed to be expanded to support a growing clinical review network, the University of Florida Brain Institute's demands for neuro-imaging, Biomedical Engineering's imaging sciences, and an electronic teaching file. Each of the groups presented a different set of problems for the designers of the system. In addition, the radiologists did not want to see nay loss of performance as new users were added.

Bone age assessment of children using a hand x-ray image is traditionally performed by comparing it with an atlas of a limited number of images. This method is not accurate due to the small homogeneous sample of images in the atlas, and the comparison is done qualitatively. A digital hand atlas, on the other hand, can circumvent these disadvantages by collecting a large sample size, identifying the ethnic origins, and using quantitative parameters relevant to bone age for comparison. This paper describes a general framework of the digital hand atlas and how it can be used to assess the skeletal growth of children.

We describe our experience in the design, installation and clinical evaluation o fan ultra-reliable PACS - a system in which the fundamental design constraint was system availability. This syste has ben constructed using commercial, off-the-shelf hardware and software, using an open system, standards-based approach. The system is deployed in the film-free Department of Pediatric Radiology at the Astrid Lindgren Barnsjukhus a nit of the Karolinska Institute in Stockholm, Sweden.

The Medical Information, Communication and Archive System (MICAS) is a multi-modality integrated image management system that is seamlessly integrated with the Radiology Information System (RIS). This project was initiated in the summer of 1995 with the first phase being installed during the first half of 1997 and the second phase installed during the summer of 1998. Phase II enhancements include a permanent archive, automated workflow including modality worklist, study caches, NT diagnostic workstations with all components adhering to Digital Imaging and Communications in Medicine (DICOM) standards. This multi-vendor phased approach to PACS implementation is designed as an enterprise-wide PACS to provide images and reports throughout our healthcare network. MICAS demonstrates that aa multi-vendor open system phased approach to PACS is feasible, cost-effective, and has significant advantages over a single vendor implementation.

Information system modeling has historically been relegated to a low priority among the designers of information systems. Often times, there is a rush to design and implement hardware and software solutions after only the briefest assessments of the domain requirements. Although this process results in a rapid development cycle, the system usually does not satisfy the needs of the users and the developers are forced to re-program certain aspects of the system. It would be much better to create an accurate model of the system based on the domain needs so that the implementation of the solution satisfies the needs of the users immediately. It would also be advantageous to build extensibility into the model so that updates to the system could be carried out in an organized fashion. The significance of this research is the development of a new formal framework for the construction of a multimedia medical information system. This formal framework is constructed using visual modeling which provides a way of thinking about problems using models organized around real- world ideas. These models provide an abstract way to view complex problems, making them easier for one to understand. The formal framework is the result of an object-oriented analysis and design process that translates the systems requirements and functionality into software models. The usefulness of this information framework is demonstrated with two different applications in epilepsy research and care, i.e., surgical planning of epilepsy and decision threshold determination.

Real-time teleconsultation can be a useful tool for the handling of neuroradiological emergency case in remote locations. Unlike with teleradiology, which describes a mere transmission of images for remote review. Teleconsultation allows physicians to interactively discuss images and findings by means of image transmission, bi-directional remote manipulation and audiovisual communication. This paper describes the communication model, implementation and clinical evaluation of such a Teleconsultation system.

An ongoing PACS project at our facility has been expanded to include providing and managing images used for routine clinical operation of the department of radiation oncology. The intent of our investigation has been to enable out clinical radiotherapy service to enter the tele-medicine environment through the use of a PACS system initially implemented in the department of radiology. The backbone for the imaging network includes five CT and three MR scanners located across three imaging centers. A PC workstation in the department of radiation oncology was used to transmit CT imags to a satellite facility located approximately 60 miles from the primary center. Chest CT images were used to analyze network transmission performance. Connectivity established between the primary department and satellite has fulfilled all image criteria required by the oncologist. Establishing the link tot eh oncologist at the satellite diminished bottlenecking of imaging related tasks at the primary facility due to physician absence. A 30:1 compression ratio using a wavelet-based algorithm provided clinically acceptable images treatment planning. Clinical radiotherapy images can be effectively managed in a wide- area-network to link satellite facilities to larger clinical centers.

The purpose of this project is to investigate the feasibility to remotely manage mammography examinations in real time, which is defined as mammography telemanagement. In such a scenario, the remotely located expert mammographer needs to view newly generated images and communicate with on-site technologist before a patient leaves the exam room. Therefore, almost real-time transmission of large volume digital mammograms between these two parties must be available. A digital telemammography test-bed has been setup between two clinical facilities in University of California, San Francisco. Both the hardware and software components of the system are discussed. Digital mammogram transmission between two campuses, however, is not yet optimal. Several methods are presented to improve the image availability. By implementing these schemes, the total time for transferring one digital mammogram from the FFDM to the remote expert workstation is reduced form 42 sec to 6 sec. It is concluded that, with improved system design and extended software capabilities, it is feasible to explore real-time telemanagement protocol in telemammography.

The purpose of the study was to evaluate the effects of lossy compression on grayscale US images to determine how much compression can be applied, and still have the images be 'acceptable for diagnostic purposes'. The study considered how the acquisition technique influences how much compression can be applied. For DICOM digital images, the study considered the how text affects the compressibility of the image. The lossy compression technique that were considered include JPEG, Set Partitioning in Hierarchical Trees Wavelet, and a Modified version of SPIHT Wavelet.

The purpose of this study was to assess the rate of failure of the high resolution monitors used for primary diagnosis in a filmless radiology department and to analyze the type of problems encountered as well as the action taken to report the monitors. Data were collected from PACS service logs to determine rates of monitor adjustment and replacement, the symptoms reported, and the action taken. Analysis of monitor service records demonstrated a high rate of monitor replacement resulting in a relatively short 'life expectancy of 2.4 years. The result of this study support our subjective impression and those of other colleagues in the PACS community of an unacceptably high monitor failure rate with 2,000 pixel monitors used for primary diagnosis. Requests for proposals for PACS and service contracts must carefully specify requirements for monitor images quality and conditions under which the vendor is required to replace these monitors.

The purpose of this paper is to analyze the incremental costs of PACS and computed Radiography and to evaluate the key factors affecting a cost-analysis for PACS.

The purpose of this research is to assess the utility of providing presets for computed radiography (CR) softcopy display, based not on the window/level settings, but on image processing applied to the image based on optimization for visualization of specific findings, pathologies, etc. Clinical chest images are acquired using an Agfa ADC 70 CR scanner, and transferred over the PACS network to an image processing station which has the capability to perform multiscale contrast equalization. The optimal image processing settings per finding are developed in conjunction with a thoracic radiologist by manipulating the multiscale image contrast amplification algorithm parameters. Softcopy display of images processed with finding-specific settings are compared with the standard default image presentation for fifty cases of each category. Comparison is scored using a five point scale with positive one and two denoting the standard presentation is preferred over the finding-specific presets, negative one and two denoting the finding-specific preset is preferred over the standard presentation, and zero denoting no difference. Presets have been developed for pneumothorax and clinical cases are currently being collected in preparation for formal clinical trials. Subjective assessments indicate a preference for the optimized-preset presentation of images over the standard default, particularly by inexperienced radiology residents and referring clinicians.

We have proposed a new user interface with workflow customization, implemented and evaluted in Endoscopy Department Mini-PACS that has been introduced and routinely used for two years at Toshiba General Hospital. We have set some task at endoscopy image acquisition units during examinations for two different types of user interfaces and compared performance. One is a command-button based operation using a remote control, and another is that with eight graphic buttons which are displayed on a CRT monitor and can be customized. Results of the two-year study show that mean number of input diagnosis codes per examination with graphic and customized interface is significantly greater than that with conventional interface. Also, mean time to complete one upper gastric endoscopy examination with new user interface is about 17 percent less than that with conventional interface. These result suggest that systems with the visualized and customized operation and feedback encourages physicians to use more functions and to compete tasks more efficiently than systems with conventional command-button based user interfaces.

Room design can have a major on radiologist productivity in a soft-copy reading environment. Several factors must be taken into account to optimize the radiologist's reading room, including lighting. The purpose of this study was to utilize the result of pervious research on the effect of ambient light on operator fatigue, to make specific design recommendations to enhance radiologist productivity in a filmless reading environment. One hundred musculoskeletal exams were interpreted by four radiologists, experienced with PACS, using a 2.0K X 1.6K four-monitor workstation. Radiologists were asked to provide subjective levels of fatigue during the reading sessions with varying levels of ambient light. Participating radiologists were surveyed as to specific factors contributing to fatigue in the current room design and asked to make recommendations to enhance productivity. The architectural literature was reviewed and specific modifications to reading room design were proposed to optimize lighting conditions in a filmless environment. Quantitative data demonstrated lower levels of ambient light optimized radiologist productivity in soft-copy interpretation by increasing interpretation accuracy and reducing levels of operator fatigue. A number of recommendations to further enhance room design were identified through radiologist surveys and review of the literature including use of separate task lighting, antiglare filters, neutral-colored surfaces, and partitions to separate individual workstations. Task lighting can be utilized in either a fixed or movable form, and be controlled by the radiologist through use of a dimmer. Design considerations of the PACS reading room are an important determinant of technology acceptance, overall work quality, and radiologist productivity. While considered by some to be a 'minor detail' in overall design, lighting plays a major role in productivity, and should be considered when designing the 'ideal PACS reading room'.

The authors developed a diagnostic radiology display station that makes use of a minimal GUI. The display paradigm is based on concepts identified by Krupinski and other sand the authors' experience with earlier display stations both in the military and commercial environments. A comparison with this display paradigm and the more common paradigms in use in current commercial display will be given. The advantages and disadvantages of each will be discussed. The display station was implemented using off the shelf hardware and software components. It is based on the Windows NT operating system. The software supports up to four monitors in a portrait configuration with a resolution of 2.5K X 2K. The display station presents the radiologist with a dark and non-distracting reading background. It supports the most frequently used display operations through a mouse interface, without standard GUI icons, buttons, menus and lists. Display of reports and reading lists is supported via commercial HIS/RIS interface engines. Clinical usage result from a beta test at the Hospital of the University of Pennsylvania will be presented. Early results indicate that the minimal GUI paradigm improves workflow and increases reading speed. However, the improvement in workflow was out- weighted by the display station's lack of integration with a HIS/RIS.

Workflow management (WfM) is an emerging field of medical information technology. It appears as a promising key technology to model, optimize and automate processes, for the sake of improved efficiency, reduced costs and improved patient care. The Application of WfM concepts requires the standardization of architectures and interfaces. A component of central interest proposed in this report is a generic work list handler: A standardized interface between a workflow enactment service and application system. Application systems with embedded work list handlers will be called 'Workflow Enabled Application Systems'. In this paper we discus functional requirements of work list handlers, as well as their integration into workflow architectures and interfaces. To lay the foundation for this specification, basic workflow terminology, the fundamentals of workflow management and - later in the paper - the available standards as defined by the Workflow Management Coalition are briefly reviewed.

A majority of distributed applications in Radiology are being developed and deployed without serious regard to their impact on currently deployed networks or how various network configurations impact end-user response-time. Typically the blame for these delays are directed unthinkingly at the existing network bandwidth. A more thoughtful planning process would consists of analyzing the latency in the various components of the transmission process: the network, computer hardware and computer software processes. We have developed a methodology for the analysis of imaging network workflow, which has been applied to the ultrasound component of the PACS at the University of Washington.

To evaluate the changes in workflow, in the radiology department, after switching from a film-based image management system to a picture archival and communication system.

The purpose of this paper is to examine the effects of PACS installation on the tasks related to the performance and interpretation of diagnostic radiological examinations.

The purpose of this study was to examine the effects of lossy image compression on the quality of digital radiographic images and to compare the resolution properties of the three image compression algorithms (JPEG) on digital radiographic images using the Modulation Transfer Function (MTF). A single point source of Tc^99m was scanned by a Gamma camera and its image was compressed by JPEG, wavelet and fractal algorithms at various compression levels. The PSFs for the original and compressed images were generated in Matlab 5.0. This was done by analyzing the pixel values along a direction through the center of the point source on each image. The MTF for each image was then calculated by Fourier transform of its PSF. The resolution properties of each compression techniques were presented. It has been found that the resolution properties of the compressed levels and algorithms are not straightforward.

This paper discusses the application of the latest internet security technology to tele-radiology/PACS design. The internet has been growing at an explosive rate and tele- radiology is riding the wave of internet growth. However, since the internet is made up of an open set of protocols, securing confidential information has been a top priority of recent research. This paper discusses the security issue of building internet-based tele-radiology system and how to apply a new security technology to fill the security needs of such systems.

In this paper, we present the interpixel redundancy between the neighboring pixels and exploit the intensity similarities of the them in serial scan vectors of the images to develop a simple system for a lossless image compression scheme and show that the process is reversible. This algorithm is called Neighboring Zero Coding (NZC); it is based on the common characteristic of that imags as neighboring pixels are highly correlated. The proposed method is a kind of integration in the coding phase and it is a form of prediction in the decoding phase, it can integrate more than 65 percent of the image coefficient to zeros. The NZC method resulting in, on average, lossless compression to about 1.65 b/pixel from 8 bits with a different high-resolution digitized computed tomography and magnetic resonance images with comparable signal to noise ratio, in addition, the algorithm coding and decoding procedure are extremely fast.

Clinics have to deal currently with hundreds of 3D images a day. The processing and visualization using currently affordable systems is very costly and slow. The present work shows the features of a software integrated parallel computing package developed at the Universidad Politecnica de Valencia (UPV), under the European Project HIPERCIR, which is aimed at reducing the time and requirements for processing and visualizing the 3D images with low-cost solutions, such as networks of PCs running standard operating systems. HIPERCIR is targeted to Radiology Departments of Hospitals and Radiology System Providers to provide them with a tool for easing the day-to-day diagnosis. This project is being developed by a consortium formed by medical image processing and parallel computing experts from the Computing Systems Department of the UPV, experts on biomedical software and radiology and tomography clinic experts.

This paper presents an approach for automatically assign histologically meaningful labels to tissue slide images. This approach is implemented as part of a larger system, I- Browse, which combines iconic and semantic content for intelligent image browsing. Our approach partitioned an input image into a number of subimages. A set of texture features based on Gabor filterings and color histogram which capture the visual characteristics of each of the subimages were computed. These image feature measurements then form the input to a pattern classifier which gives an initial coarse label assignment to subimages based on a hierarchical clustering of these image features. To facilitate supervised training of the classifier, a knowledge elicitation tool was developed which allows a histopathologist to assign histological terms to a sample of sub-images obtained from digitized tissue imags. The initial labels and their spatial distribution were then analyzed by a semantic analyzer with the help of a knowledge base which contains prior knowledge of the expected visual appearance of histological images of an organ. The label assigned to the subimages were successive refined through a process of relevant feedback.

DICOM Supplement 32 defined Information Object Definitions (IODs) and corresponding Storage SOP Classes for Digital X- ray (DX) projection image. The scope of the Supplement was to support DX imags produced by Flat Panel (FP) detectors, Computed Radiography (CR) and Digitized Film (DF) images. We thought it may be necessary to have more attributes to fully describe CR and DF images, especially those related to QA. Using Object Oriented Analysis, we analyzed the acquisition process of x-ray projection image and extracted attributes which should be added to DX IOD. The DX equipment should include x-ray equipments as well as imaging devices. The imaging devices were classified into three classes, CR, DF and FP Equipment Class, and the corresponding Information Modules (IM) were defined. The attributes of each class were classified in to two IMs, the Specification Modules and the Condition/Acquisition Modules. All the added elements were user optional attributes. The newly defined objects were, therefore, classified into Extended DX SOP Class and could be processed by many DICOM SCPs/SCUs conforming to DICOM DX IOD defined in Supplement 32.

Automatic background recognition and removal is an important step for the implementation of automatic soft copy display in PACS and teleradiology. We developed a method that performs very well in pediatric and regular ICU CR images. We have recently modified the method to accommodate special situations including irregular shaped and circular collimators, and multiple exposures on one CR imaging plate. Interesting cases are presented to demonstrate the effect of before and after the background removal of the image.

A prototype secure archiving device have been developed for digital record systems that has the same preservability, viewability, and integrity as paper and film based systems. The device can manage a variety of digital recording media with the security level. We evaluated the device in a medical environment by connecting it to an existing medical record archiving system. The device satisfies the criteria that the Japanese Ministry of Health and Welfare has announced for regulating digital medical records.

A frequently used assessment method of bone age is atlas matching by a radiological examination of a hand image against a reference set of atlas patterns of normal standards. We are in a process of developing a digital hand atlas with a large standard set of normal hand and wrist images that reflect the skeletal maturity, race and sex difference, and current child development. The digital hand atlas will be used for a computer-aided bone age assessment via Web. We have designed and partially implemented a computer-aided diagnostic (CAD) system for Web-based bone age assessment. The system consists of a digital hand atlas, a relational image database and a Web-based user interface. The digital atlas is based on a large standard set of normal hand an wrist images with extracted bone objects and quantitative features. The image database uses a content- based indexing to organize the hand images and their attributes and present to users in a structured way. The Web-based user interface allows users to interact with the hand image database from browsers. Users can use a Web browser to push a clinical hand image to the CAD server for a bone age assessment. Quantitative features on the examined image, which reflect the skeletal maturity, will be extracted and compared with patterns from the atlas database to assess the bone age. The relevant reference imags and the final assessment report will be sent back to the user's browser via Web. The digital atlas will remove the disadvantages of the currently out-of-date one and allow the bone age assessment to be computerized and done conveniently via Web. In this paper, we present the system design and Web-based client-server model for computer-assisted bone age assessment and our initial implementation of the digital atlas database.

As increasing number of medical facilities are introducing PACS, the needs to interconnect PAC systems are also increased. Although the primary goal of PACS is to enable distribution of radiologic images electronically within hospital and thus assist patient care more efficiently, inter-networking of multiple facility PAC systems can create additional application area and bring about clinical impact. By inter-networking multiple facility PACS, exams can be automatically routed to the remote radiologist when the local radiologist is not available such as during the off- duty hours and vacations. Physicians and radiologists can also benefit from the inter-networking of PACS by making telesconsultation of special cases with remote subspecialty radiologists which can lead to improved diagnostic accuracy and confidence. In this study, we attempted to develop an inter-networking system among the multi-facility PAC systems which can be used for image data transfer and telesconsultation by establishing the ISDN intranet and developing a Web based DICOM white board.

With radiology departments moving into a digital environment, Quality Control (QC) has shifted from film processor monitoring, and film-screen contact tests to computed radiography (CR) calibrations, soft copy display evaluations, and thread test of the imaging chain and the supporting data flow. An analog QC plan encompasses each piece of equipment and everyone in radiology, from the radiologists providing image quality feedback and the technologists performing film processor checks, to the biomedical maintenance technicians calibrating exposure rooms, everyone has input to a good analog QC plan. The digital radiology environment is no different; it requires user and maintainer involvement at all levels. This paper will explain the Task Allocation Chart and how it fits into the QC, warranty, and maintenance continuum that must be in place for an effective installation, implementation, and operation of a PACS.

We developed a PC-based clinical workstation and implemented at Asan Medical Center in Seoul, Korea, Hardwares used were Pentium-II, 8M video memory, 64-128 MB RAM, 19 inch color monitor, and 10/100Mbps network adaptor. One of the unique features of this workstation is management tool for folders reside both in PACS short-term storage unit and local hard disk. Users can copy the entire study or part of the study to local hard disk, removable storages, or CD recorder. Even the images in private folders in PACS short-term storage can be copied to local storage devices. All images are saved as DICOM 3.0 file format with 2:1 lossless compression. We compared the prices of copy films and storage medias considering the possible savings of expensive PACS short- term storage and network traffic. Price savings of copy film is most remarkable in MR exam. Price savings arising from minimal use of short-term unit was 50,000 dollars. It as hard to calculate the price savings arising from the network usage. Off-line PC viewer is a cost-effective way of handling private folder management under the PACS environment.

We developed a tele-radiology and tele-conference system between our related hospitals. This system consisted of the image database, the WWW server, WWW browsers, high resolution CRT displays, the videoconference system and an asynchronous transfer mode (ATM) network. In advance X-ray images were stored into the Image Save And Carry magneto- optical (MO) disks, then images on the MO were transferred to the image database. The image database was created from MO disks. Total amount of images reached 100 GB and the number of the image was 65,000. The ATM network connected the hospitals each other. The ATM network device provided the permanent virtual circuit function. The transmission speed was from 6Mbit/second to 155 Mbit/second. The client station consisted of the WWW browser and the super high definition CRT display which had the 2k X 2k full color frame memory and 54 X 54 cm square display area. The result of the query was transformed to a hypertext markup language. Then a browser on a client machine displayed the result. The server could retrieve some images in about ten seconds and transmit an image from a server to a client in 2-10 seconds that depend on the network speed. At the tele- radiology, both terminals could display same image and physicians could talk each other by the videoconference system. We solved the security problems by the PVC methods and the on time password device. The ATM network showed the high transmission performance and good security. Physicians were able to use this system with no special training and this system brought us an effective utilization of the image.

Medical picture archiving and communication system (PACS), is a subject developed by combining radiology with electronic and computer network technologies. It attracts the interest of many researchers as soon as it appeared. In this paper the research status of PACS is summarized and analyzed. An applicable design is proposed, which is integrated with hospital information system and the implementation of which shows a better performance. Concepts concerning PACS are discussed.

There is evidence that digital imaging is rapidly becoming the basis of radiology practice resulting in the gradual elimination of hard copy films. Related to this trend is the ability of radiologists to provide reliable interpretations of imaging examinations using 'teleradiology.' This concern is related to film digitization technology and the diagnostic quality of the radiographic image viewed on softcopy displays. This study was undertaken to determine if there were significant differences between the accuracy of diagnoses and perceived image quality between CCD and Laser digitized images. Types of film examinations selected for digitization and softcopy interpretation in the study were intended to represent current radiology practice and the expectation that 'teleradiology' may be used for primary diagnosis.