Enterprise-scale image distribution with a Web PACS

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.     

Data clustering and other archive retrieval strategies for teleradiology and picture archiving and communication systems

A key advantage in the conversion from film-based to digital radiology is the possibility of a long-term on line electronic archival of patient studies. The popular approach based on optical disk jukeboxes for the long-term archive and magnetic disk storage for data caching is not economically attractive because of the cost of both the jukebox and the medium. Strategies for extending the archival system design with a tape jukebox have been studied. The proposed strategy calls for the use of high-ratio lossy compression together with low-cost tape storage to make long-term on line archiving more affordable. An intelligent prefetching algorithm based on hospital information system and radiologic information system triggers, which in turn are augmented by manual case preparation, can effectively overcome the longer latency of ad hoc retrievals. This longer latency is caused by both system-level bottlenecks and the sequential access constraint of the tape drive. Strategies for image clustering and tape allocation by patient classification also enhance retrieval efficiency. This archival design using image compression, prefetching, and clustering could be implemented in many of the existing teleradiology and picture archiving and communication systems.     

High-resolution digital teleradiology: A perspective

Teleradiology has come a long way, from analog transmission systems using slow-scan television over standard telephone lines, to present-day, commercially available, microcomputer-based, low-resolution teleradiology systems. However, there exists a need to address the high-resolution end of the medical imaging categories, namely chest radiographs and mammograms, to firmly establish teleradiology. The availability of high-resolution image digitizers, display units, and digital hard copiers has made high-resolution digital teleradiology a feasible concept. Although the use of satellite channels can speed up the transmission of radiographic image data, with widespread acceptance of high-resolution teleradiology systems in the foreseeable future, the sheer amount of data involved in this field will give rise to problems of data transmission and storage. Data compression schemes can bring down the amount of data handled and can have a great economic impact on future teleradiology systems. We have developed a number of compression techniques for reversible compression of medical images. Our experiments have shown that lossless compression of the order of 4:1 is possible for a class of high-resolution medical images. Use of pattern recognition techniques offers the potential to bring down these data rates even further. We plan to use these techniques in a prototype high-resolution teleradiology system being developed. In this paper, we trace some of the developments in teleradiology and image data compression, and present a perspective for teleradiology in the 1990s.     

Teleradiology at the tertiary-level Women's and Children's Hospital in South Australia.

This article relates to a teleradiology trial undertaken in 1998-1999 at the Women's and Children's Hospital (WCH) in Adelaide, the capital of South Australia. The trial involved linking the hospital to a range of rural and remote sites in South Australia and the Northern Territory. The main aim of the project was to evaluate the advantages, limitations, benefits, and costs of a teleradiology service provided by WCH. The major finding from the study is that for a tertiary hospital providing second opinions in complex medical cases, a new form of business justification is required for teleradiology. The justification would include an emphasis on the range of high-level services that a subspecialist hospital such as the WCH can provide. The justification would also include the range of benefits to different parties, particularly the patient, and the intangible nature of many of the benefits.     

Design of a cooperative teleradiology system.

The article describes a teleradiology system intended to provide a user-friendly environment for exchanging images and working cooperatively on them. With the development of a hospital-wide picture archiving and communication system (PACS), the University Hospital of Geneva and several other health institutions in the region became interested in teleradiology. Because of the heterogeneous needs of the potential participants, the following requirements were identified: (1) remote consultation and interpretation of images; and (2) cooperative interpretation of medical images, allowing real-time interaction between physicians. To satisfy these needs, a multipoint teleradiology system has been implemented that incorporates an innovative image display and manipulation software program known as OSIRIS, which supports the full spectrum of imaging modalities. Images and data are transmitted over the public telecommunications Integrated Services Digital Network (ISDN). To accommodate different computing environments at the various locations, platform-independent software has been designed that has the same "look and feel" for PC-Windows, Macintosh, and UNIX-X11 work-stations. The teleradiology system can be used in two modes: synchronous (cooperative) or asynchronous. Special efforts have been made in the development of the synchronous mode. Within the European Telemed Project, a specific protocol has been designed to allow cooperative work between remotely located workstations.     

Web-based Diagnostic Imaging Service Using XML Forms

Traditionally, radiology has been conceived as a support department providing patient scanning services to the other clinical departments in a hospital. However, recent advancements in networking technology and related information systems such as picture archiving and communication system (PACS) and radiology information system (RIS) provide new opportunities for inventing different types of diagnostic imaging businesses such as teleradiology. In this article, we examined the business processes of currently operating imaging centers and proposed a prototype of an information system that can facilitate their workflows in a more efficient way. The principal component of our proposed system is a report management module built on extensible markup language (XML) technologies that allows much flexibility and convenience for both imaging technicians and radiologists.     

Design of a high-speed,high-resolution teleradiology network

A teleradiology system acquires radiographic images from one location and transmits them to one or more distant sites where they are displayed and/or converted to hard-copy film recordings. The long-term goal of teleradiology research is to show that teleradiology systems can provide diagnostically equivalent results when compared with conventional radiographic film interpretation. If this hypothesis is proven, provision of the following radiology services will be improved: (1) providing for primary interpretation of radiological images for patients in underserved areas as well as in other medical facilities; (2) integration of radiological services for multihospital/clinic health care provider consortiums; (3) improving emergency service and intensive care unit coverage; (4) offering consulting-at-a-distance with subspecialty radiologists; and (5) providing radiologists in the community or in rural areas with immediate access to large academic centers for help in the interpretation of difficult and problematic cases. We are designing a high-speed, high-resolution teleradiology network that will communicate between our level 3 medical center and several outlying medical centers within the metropolitan area. Computed tomography (CT), magnetic resonance (MR), and screen-film examinations will be digitized to 2,000 x 2,000 or 4,000 x 4,000 pixels at the remote sites, transmitted to the central referral facility, and sent to a laser film printer, replicating the original film. This film may then be used for primary diagnosis, overreading/consultative purposes, or for emergency department preparation. Inherently digital modality data (eg, MR and CT) can be sent without digitization of the multiformat film if desired.     

Japanese experience of telemedicine in oncology

We started telemedicine projects from 1990 with a telepathology system within Tsukiji Campus of National Cancer Center. In 1994, we connected Tsukiji Campus and Kashiwa Campus by 6 Mbps optical fiber leased line using IP protocol for data transmission, for teleconference, telepathology, and teleradiology projects. We also started connection of regional cancer centers and are now forming a cancer center network of 14 cancer centers. We are at present organizing 130 teleconferences per year with an attendance of more than 16000 people as summary. We have also used a high-resolution image transferring system, such as SHD (2000 pixelsx2000 pixels resolution) system on one side, and an economical telemedicine system using JAVA and a WWW browser (NCC_image) on the other side. We think that providing information is another field of telemedicine. We began the experimental gopher and WWW service in 1993. We are now providing official up-to-date cancer information for patients and healthcare professionals. We are getting more than 400000 hits per month. We are also providing a teleconference video session which is held every week on the Internet using a Real Video system with synchronized slide presentation on the WWW browser. We are also organizing a Cancer Image Reference Database System including DICOM images with viewer software. This paper is a summary of the telemedicine projects performed at the National Cancer Center.     

基于CORBA的医院信息系统与PACS的分布式集成研究

在实际医学应用中 ,医生需要及时获得病人的有关图像和文本记录信息。这些信息有助于医生进行病历诊断 ,临床试验和研究分析。但是这些信息分布零乱 ,并且位于不同的系统上 ,如图像管理和通信系统 (Picturearchiving and comm unication information systems,PACS) ,医院信息系统 (Hospital inform ation systems,HIS)等 ,这些系统使用不同的标准和协议 ,并且都不支持分布式操作 ,使系统间信息不能完全共享。为了实现各种医学系统间的分布式操作和信息的共享 ,本文结合当前流行的 WWW技术 ,利用分布式处理软件 (Common object requestbroker architecture,CORBA) ,提出了一种基于 WEB的 PACS和 HIS分布式集成方法 ,该方法将图像和文本信息系统及各种医学应用都看作是 CORBA组件对象 ,把对这些系统和应用的操作都当作是对应用对象的处理 ,利用面向对象的技术实现了对 PACS和 HIS系统的分布式集成和互操作 ,并且利用 WEB技术实现了信息的共享     

A Review of Medical Image Watermarking Requirements for Teleradiology

Teleradiology allows medical images to be transmitted over electronic networks for clinical interpretation and for improved healthcare access, delivery, and standards. Although such remote transmission of the images is raising various new and complex legal and ethical issues, including image retention and fraud, privacy, malpractice liability, etc., considerations of the security measures used in teleradiology remain unchanged. Addressing this problem naturally warrants investigations on the security measures for their relative functional limitations and for the scope of considering them further. In this paper, starting with various security and privacy standards, the security requirements of medical images as well as expected threats in teleradiology are reviewed. This will make it possible to determine the limitations of the conventional measures used against the expected threats. Furthermore, we thoroughly study the utilization of digital watermarking for teleradiology. Following the key attributes and roles of various watermarking parameters, justification for watermarking over conventional security measures is made in terms of their various objectives, properties, and requirements. We also outline the main objectives of medical image watermarking for teleradiology and provide recommendations on suitable watermarking techniques and their characterization. Finally, concluding remarks and directions for future research are presented.     

High-Volume Teleradiology Service: Focus on Radiologist Satisfaction

In 1998 we surveyed our radiologists on teleradiology satisfaction. Results were generally positive. In 2002 we experienced a sevenfold case increase in teleradiology volume. The present study surveyed the radiologists again. The hypothesis was that, with increased case volume and radiologist experience with the system, ratings would increase. Image quality was excellent/good, although plain film and ultra sound (US) had more fair/poor ratings. Monitors, navigation, image processing, and Web-based reporting were rated as excellent/good. The voice-recognition system was rated poorly. Diagnostic confidence was about the same as for film. Exceptions were magnetic resonance imaging (MRI) US, and plain film. Up to 10% of cases are unreadable because of poor image quality, not enough images, or inadequate patient history. Overall, the radiologists are satisfied, although some improvements can be made.     

Clinical computer applications in the radiology department

The information society is currently developing. In the field of radiology, the PACS (picture archiving and communication system) and teleradiology are widely employed in medical practice. The Ministry of Health and Welfare (MHW) reported that physicians should consider some problems in Telemedicine in December 1997. The technology of storage media is improving and we encourage the standardization of data formatting and the transmission protocol to utilize medical electronic information. Several standards exist in the medical imaging field, the DICOM (digital imaging and communications in medicine) standard, the IS&C (image save and carry) standard and the Common Standard that the Medical Information System Development Center (MEDIS-DC) defined for the electronic storage. The PACS requires high transmission speed, integrated services digital network and an asynchronous transfer mode switching system. The MHW needed a technical requirement for the electronic image storage without films in March 1994. The requirement was divided into three parts, (1) security, (2) long-term reproducibility, (3) common usage. The MEDIS-DC published the Common Standards for electronic storage in 1996. When we use the PACS via network, we must consider the security. The present network may have low security, and falsification, such as illegal login may occur. In the future, these problems will be solved, and the network-wide PACS will likely become a commonly used system.     

Parlaying digital imaging and communications in medicine and open architecture to our advantage: The new Department of Defense picture archiving and communications system

The Department of Defense (DoD) undertook a major systems specification, acquisition, and implementation project of multivendor picture archiving and communications system (PACS) and teleradiology systems during 1997 with deployment of the first systems in 1998. These systems differ from their DoD predecessor system in being multivendor in origin, specifying adherence to the developing Digital Imaging and Communications in Medicine (DICOM) 3.0 standard and all of its service classes, emphasizing open architecture, using personal computer (PC) and web-based image viewing access, having radiologic telepresence over large geographic areas as a primary focus of implementation, and requiring bidirectional interfacing with the DoD hospital information system (HIS). The benefits and advantages to the military healthcare system accrue through the enabling of a seamless implementation of a virtual radiology operational environment throughout this vast healthcare organization providing efficient general and subspecialty radiologic interpretive and consultative services for our medical beneficiaries to any healthcare provider, anywhere and at any time of the night or day.     

Patient information extraction in digitized radiography

Digital imagery is gradually replacing the traditional radiograph with the development of digital radiography and film scanner. This report presents a new method to extract the patient information number (PIN) field automatically from the film-scanned image using image analysis technique. To evaluate the PIN field extraction algorithm, 2 formats of label acquired from 2 different hospitals are tested. Given the available films with no constraints on the way the labels are written and positioned, the correct extraction rates are 73% and 84%, respectively. This extracted PIN information can link with Radiology Information System (RIS) or Hospital Information System (HIS), and the image scanned from the film then can be filed into the database automatically. The efficiency this method offers can simplify greatly the image filing process and improve the user friendliness of the overall image digitization system. Moreover, compared with the bar code reader, it solves the automatic information input problem in a very economical way. The authors believe the success of this technique will benefit the development of the PACS (Picture Archiving and Communication System) and teleradiology.     

User Interface of a Teleradiology System for the MR Assessment of Multiple Sclerosis

The aim of this study was to assess the image display of a web-based teleradiology system that uses a common web browser and has no need of proprietary applets, plug-ins, or dedicated software for DICOM display. The teleradiology system (TS) is connected to the Internet by ADSL and to radiological modalities using the DICOM standard with TCP/IP. Images were displayed on a PC through Internet connection with the remote TS using a common web browser. MS lesion number and volume in T1- and T2-weighted images (T1w and T2w, respectively) of 30 brain MR studies were quantified using both the TS and a conventional software. Wilcoxon signed ranks test and intraclass correlation coefficient (ICC) were used to assess the variability and concordance between intra- and inter-observer and TS and conventional DICOM viewer, setting significance at p < 0.05. No significant differences in T1w and T2w volumes between the TS and the conventional software were found by either operator. The ICC results showed a high level of inter-operator agreement in volume estimation in T1w and T2w images using the two systems. Quantitative assessment of MS lesion volumes in T1w and T2w images with a user interface of a teleradiology system that allows the consultation by means of a common web browser, without the need for proprietary plug-ins, applets, or dedicated software for DICOM display showed no significant differences from, and almost complete agreement with, conventional DICOM viewers.     

“Evaluation of a Very Low-Cost and Simple Teleradiology Technique”

This paper describes and analyzes a proposed solution of fundamental limitative factor of teleradiology to overcome the teleradiology usages problems in underdeveloped and developing countries. The goal is to achieve a very simple and cost-efficient way to take advantage of teleradiology in anywhere even in remote and rural areas. To meet the goal of this study, the following methodology which is consists of two main procedures was done: (1) Using a digital camera in order to provide a digital image from radiographs. (2) Using an image compression tool in order to compress digital images. The results showed that there is no significant difference between digital images (non-compress and compress images) and radiographic films. Also, there was a logic relationship between the diagnostic quality and diagnostic accuracy. Since the maximum percent of diagnostic accuracy can be seen among “Good” quality images and the minimum to was related “Poor”. The results of our study indicate that a digital camera could be utilized to capture digital images from radiographic films of chest x-ray. To reduce the size of digital images, a lossy compression technique could be applied at compression percent of 50 or less without any significant differences. The compressed images can be sent easily by email to other places for consultation and also they can be stored with a smaller size.     

Health care providers' perceptions of telemedicine services.

OBJECTIVE: To assess the level of consensus among the administrative and health care leaders at rural Iowa hospitals regarding service gaps and priorities for developing telemedicine services. METHODS: In the summer of 1994, a survey was conducted of all rural hospital chief executive officers, chiefs of medical staffs, and directors of nursing in Iowa concerning their perceptions of telemedicine services. RESULTS: With the exception of teleradiology, few clinical specialties received high ratings as areas of need or priorities for the development of telemedicine. There was a general lack of agreement among respondents from the same hospital on such priorities. In contrast, respondents expressed higher priorities for the development of telemedicine-based educational services. CONCLUSIONS: The interest in teleradiology is consistent with the fact that teleradiology has been more thoroughly tested for medical efficacy than other telemedicine applications. Continuing medical education may represent another potential for widespread successful telemedicine application. Financial issues were reported as the greatest barriers to the development of telemedicine systems.     

General Consumer Communication Tools for Improved Image Management and Communication in Medicine

We elected to explore new technologies emerging on the general consumer market that can improve and facilitate image and data communication in medical and clinical environment. These new technologies developed for communication and storage of data can improve the user convenience and facilitate the communication and transport of images and related data beyond the usual limits and restrictions of a traditional picture archiving and communication systems (PACS) network. We specifically tested and implemented three new technologies provided on Apple computer platforms. (1) We adopted the iPod, a MP3 portable player with a hard disk storage, to easily and quickly move large number of DICOM images. (2) We adopted iChat, a videoconference and instant-messaging software, to transmit DICOM images in real time to a distant computer for conferencing teleradiology. (3) Finally, we developed a direct secure interface to use the iDisk service, a file-sharing service based on the WebDAV technology, to send and share DICOM files between distant computers. These three technologies were integrated in a new open-source image navigation and display software called OsiriX allowing for manipulation and communication of multimodality and multidimensional DICOM image data sets. This software is freely available as an open-source project at . Our experience showed that the implementation of these technologies allowed us to significantly enhance the existing PACS with valuable new features without any additional investment or the need for complex extensions of our infrastructure. The added features such as teleradiology, secure and convenient image and data communication, and the use of external data storage services open the gate to a much broader extension of our imaging infrastructure to the outside world.     

A real time collaboration system for teleradiology consultation

Real time collaboration systems, in which participants share multimedia data and applications in real time, have attracted many researchers in recent years. A teleradiology consultation system based on the real time collaboration technology is presented in this paper. Under the platform-independence consideration, Java technologies are employed to construct the system. Applying this system, an off-duty on-call radiologist can make diagnoses and report easily by viewing the transferred images at home. Owing to the accessibility of image, all users can examine and manipulate images consistently such that a secluded hospital can be assisted to hold remote consultation. To reduce the network transmission time, the command-passing and local command execution techniques are utilized to achieve the screen synchronization. A pointer function is also developed to maintain the cursor consistency in a more efficient manner during consultation when a detail indication of the examined image is needed. Besides, a dialog window is also designed for on-line conversation. Since Java programs can run on heterogeneous platforms, the need for system maintenance and user training can be substantially reduced.     

A security architecture for interconnecting health information systems

Several hereditary and other chronic diseases necessitate continuous and complicated health care procedures, typically offered in different, often distant, health care units. Inevitably, the medical records of patients suffering from such diseases become complex, grow in size very fast and are scattered all over the units involved in the care process, hindering communication of information between health care professionals. Web-based electronic medical records have been recently proposed as the solution to the above problem, facilitating the interconnection of the health care units in the sense that health care professionals can now access the complete medical record of the patient, even if it is distributed in several remote units. However, by allowing users to access information from virtually anywhere, the universe of ineligible people who may attempt to harm the system is dramatically expanded, thus severely complicating the design and implementation of a secure environment.This paper presents a security architecture that has been mainly designed for providing authentication and authorization services in web-based distributed systems. The architecture has been based on a role-based access scheme and on the implementation of an intelligent security agent per site (i.e. health care unit). This intelligent security agent: (a) authenticates the users, local or remote, that can access the local resources; (b) assigns, through temporary certificates, access privileges to the authenticated users in accordance to their role; and (c) communicates to other sites (through the respective security agents) information about the local users that may need to access information stored in other sites, as well as about local resources that can be accessed remotely.