Proceedings Volume 4685

Medical Imaging 2002: PACS and Integrated Medical Information Systems: Design and Evaluation

Eliot L. Siegel, H. K. Huang
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Proceedings Volume 4685

Medical Imaging 2002: PACS and Integrated Medical Information Systems: Design and Evaluation

Eliot L. Siegel, H. K. Huang
View the digital version of this volume at SPIE Digital Libarary.

Volume Details

Date Published: 16 May 2002
Contents: 9 Sessions, 54 Papers, 0 Presentations
Conference: Medical Imaging 2002 2002
Volume Number: 4685

Table of Contents

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Table of Contents

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  • Practical Experience
  • PACS in Korea: State of the Art
  • Archive and Database
  • PACS Special Topics
  • Workflow
  • Connectivity
  • DICOM
  • Security/Fault Tolerance
  • Poster Session
Practical Experience
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Specification and evaluation of a regional PACS in the SaxTeleMed project
Heinz U. Lemke, W. Niederlag, H. Heuser
During the early development phase of PACS, its implementation was mainly a matter of the radiological department of a hospital. This is changing rapidly and PACS planning and realization is increasingly seen in the context of a hospital-wide approach. With a growth of networking amongst healthcare institutions and the growing relevance of teleradiological scenarios, new strategies must be followed which take not only local but also regional and global aspects of PACS into consideration. One such regional PACS project was initiated by the Ministry of Social Welfare of the Free State of Saxony in Germany. This 'reference model program for the digitization of imaging procedures and communication of images between hospitals in the free state of Saxony' (SaxTeleMed) covers seven regional projects distributed throughout Saxony. Each regional project is organized around so called lead hospitals, which network with other cooperating hospitals and medical practices. The regional reference projects are designed to be largely independent from one another. In some instances, however, a network connection between reference projects is also considered. Altogether, 39 hospitals and medical centers are involved in the model program. The aim of this program is to test the technical, organizational, legal and economic problems in the area of digitization and networking within the free State of Saxony. With the knowledge gained it is expected to improve future investment decisions in healthcare and above all to implement secure systems.
PACS according to Murphy: what can and will go wrong
Janice C. Honeyman-Buck, Manuel Arreola, Meryll M. Frost
A multi-institutional PACS and electronic radiology practice is in daily operation based at the University of Florida. This system is evolving constantly as technology advances and users become more sophisticated. As the technology advances, however, more things can and do go wrong. The PACS quality control and working groups at the University have compile the problems that have been encountered is this rapidly changing environment and have designed tools or procedures to either eliminate the problems or to minimize their impact on the operation of the system. As a result, a series of automated tools have been created to correct mislabeled images, to monitor the correct operation of the system, and to inform support of problems as soon as they are discovered. In the case where automated tools cannot solve the problem, protocols have been designed and procedures developed to identify issues and resolve them before time is wasted or the system fails. Not every problem can be anticipated and solved prior to it occurring, but this work can help alert new users and perhaps even experienced users to unanticipated disasters with PACS and other technologies associated with an electronic radiology practice.
PACS technologies and reliability: are we making things better or worse?
Steven C. Horii M.D., Regina O. Redfern, Harold L. Kundel, et al.
In the process of installing picture archiving and communications (PACS) and speech recognition equipment, upgrading it, and working with previously stored digital image information, the authors encountered a number of problems. Examination of these difficulties illustrated the complex nature of our existing systems and how difficult it is, in many cases, to predict the behavior of these systems. This was found to be true even for our relatively small number of interconnected systems. The purpose of this paper is to illustrate some of the principles of understanding complex system interaction through examples from our experience. The work for this paper grew out of a number of studies we had carried out on our PACS over several years. The complex nature of our systems was evaluated through comparison of our operations with known examples of systems in other industries. Three scenarios: a network failure, a system software upgrade, and attempting to read media from an old archive showed that the major systems used in the radiology departments of many healthcare facilities (HIS, RIS, PACS, and speed recognition) are likely to interact in complex and often unpredictable ways. These interactions may be very difficult or impossible to predict, so that some plans should be made to overcome the negative aspects of the problems that result. Failures and problems, often unpredictable ones, are a likely side effect of having multiple information handling and processing systems interconnected and interoperating. Planning to avoid, or at least not be so vulnerable, to such difficulties is an important aspect of systems planning.
NGI performance for teleradiology applications
Greg T. Mogel, H. K. Huang, Fei Cao, et al.
Tele-medical imaging applications require low cost, and high-speed backbone wide area networks (WAN) to carry large amount of imaging data for rapid turn around interpretation. Current low cost commercially WAN is too slow for medical imaging applications, while high speed WAN is too costly. The next generation Internet (NGI) or Internet2 is federal initiatives for the integration of higher speed backbone communication networks (up to 2.4 Gbits/sec) as a means to replace the current inadequate Internet for many applications including medical imaging. This paper describes our preliminary experience of connecting to Internet2 for teleradiology application. A case study is given for the NGI WAN connection between Childrens Hospital Los Angeles and National Library of Medicine. NGI WAN performance for different image modalities, measured in throughput rate and application response time, were obtained and then compared to the T1 WAN connection between Childrens Hospital Los Angeles and Saint John's Health Center Santa Monica.
Web-based medical image archive system
Edward B. Suh, Steven Warach, Huey Cheung, et al.
This paper presents a Web-based medical image archive system in three-tier, client-server architecture for the storage and retrieval of medical image data, as well as patient information and clinical data. The Web-based medical image archive system was designed to meet the need of the National Institute of Neurological Disorders and Stroke for a central image repository to address questions of stroke pathophysiology and imaging biomarkers in stroke clinical trials by analyzing images obtained from a large number of clinical trials conducted by government, academic and pharmaceutical industry researchers. In the database management-tier, we designed the image storage hierarchy to accommodate large binary image data files that the database software can access in parallel. In the middle-tier, a commercial Enterprise Java Bean server and secure Web server manages user access to the image database system. User-friendly Web-interfaces and applet tools are provided in the client-tier for easy access to the image archive system over the Internet. Benchmark test results show that our three-tier image archive system yields fast system response time for uploading, downloading, and querying the image database.
PACS in Korea: State of the Art
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Evolution of filmless PACS in Korea
Hyung-Sik Choi M.D.
The growth of PACS (Picture Archiving and Communications System) market in Korea over the past 10 years is a brilliant development. In order to reach these brilliant achievements, the efforts of the Korean Society of PACS, the supports of the government on the information technology industry and the efforts of PACS companies in market expansion were all served as vital manures of the sowing time. By the end of 2001, 21% of the total Korean hospitals were under the clinical operation using filmless full PACS and it is believed to be the first incident in the world. The purpose of this paper is to look back upon the growing process of filmless PACS in Korea and analyze the cause of this tremendous growth. I believe that the Korean PACS experience would be helpful to many PACS experts who pray for a proliferation of PACS distribution.
PACS industry in Korea
PACS industry in Korea has been rapidly growing, since government had supported collaborative PACS project between industry and university hospital. In the beginning, PACS industry had focused on developing peripheral PACS solutions, while the Korea PACS society was being formed. A few companies had started developing and installing domestic large-scale full-PACS system for teaching hospitals. Several years later, many hospitals have installed full-PACS system with national policy of reimbursement for PACS exams in November 1999. Both experiences of full-PACS installation and national policy generated tremendous intellectual and technological expertise about PACS at all levels, clinical, hospital management, education, and industrial sectors. There are now more than 20 domestic PACS companies. They have enough experiences which are capable of installing a truly full-PACS system for large-scale teaching hospitals. As an example, a domestic company had installed more than 40 full-PACS systems within 2-3 years. Enough experiences of full-PACS installation in Korea lead PACS industry to start exporting their full-PACS solutions. However, further understanding and timely implementation of continuously evolving international standard and integrated healthcare enterprise concepts may be necessary for international leading of PACS technologies for the future.
Technical aspects of PACS in Korea
Korea is one of the fastest growing countries in the number of filmless hospitals. More than 70 hospitals have converted to filmless environments by adopting full PAC systems during the last two years. The patient care environment in Korean hospitals was not favorable to PACS implementation. In many out patient clinics, doctors had to see more than hundred patients a day. It was not rare for a radiologist to read several hundred of exams a day. Also, the PACS teams were mandated to acquire full scale PACS capable of incorporating not only radiological images but also color images produced in other imaging departments. In order to take root in Korean environment, the PACS in Korea had to pass through some technical modifications that included introduction of recent hardware technologies and development of new software features. This paper describes various technical aspects of PAC systems in Korea that have met difficult requirements and enabled wide spread of PAC systems to real clinical practice.
Impact of PACS in hospital management
Gham Hur, Soon-Joo Cha, Yong Han Kim, et al.
Since the low-cost, NT-based, full PACS was successfully implemented in a large-scale hospital at the end of 1999, many hospital administrators have rushed to purchase the system competitively. It is now a worldwide trend to implement the technology, but Korea has several unique environments for the fast spread of the full PACS. Since hospitals in Korea operate inpatient and outpatient clinics in the same building and use identical OCS, full integration of PACS with the OCS was relatively easy and highly efficient. The simple governing structures of the hospitals also made the decision-making process short and effective. In addition, the national health insurance reimbursement policy that started pay in the beginning of 2000 has also played a catalytic role for the swift propagation of PACS. The recent appearance of the affordable PACS gave hospital administrators the opportunity to learn and understand the role of digital imaging in the areas that are directly related to the efficiency and quality of medical services, as well as cost containment. Furthermore, PACS provided them with windows to the 'all-digital hospital,' which will lead them to realign policies in the management of the hospitals in order to compete successfully in the fast-changing world of health care.
Cost justification of filmless PACS and national policy
Jae Hoon Lim
The expense of installing PACS is high so most Korean hospitals cannot afford to purchase the system easily. We can justify the cost of PACS by considering the visible and invisible benefits. As a visible benefit we can save the cost of films and equipments for film processing. Invisible benefits of PACS is the cost of film handling. Generally, doctors spend some 25 minutes in handling X-ray films everyday and they spend 10 days (84 hours) throughout a year. Radiology technicians, nurses, orderlies and clerks also handle films and the total salary for handling films by doctors and paramedics will be considerable. Considering the visible and invisible benefits, cost of PACS is justified and PACS can be installed in every hospital, whatever their size. The Korean Society of PACS tried to make reimbursement of the cost of PACS and persuaded the government officers and eventually the Ministry of Health and Welfare decided to reimburse the use of PACS in hospitals. Based on the money reimbursed, general hospitals or university hospitals will earn enough money to purchase a PACS in 3 - 5 years. After the Korean government started to reimburse the cost of PACS, many hospitals wanted to install PACS and the number of hospitals installing PACS is soaring.
Full PACS installation in Seoul National University Hospital, Korea
HyunWoo Lim, DongOok Kim, JinYoung Ahn, et al.
Seoul National University Hospital (SNUH) is composed of two buildings and has more than 1500 beds for patients needing hospitalization. Marotech has provided full PACS to SNUH with total HIS Integration in this year. In this paper, the installation process and management experience for seven months will be presented. At SNUH, 1643.8 exams were held per day during seven month after PACS installation. It is about 40 Gigabytes per day. Two acquisition servers (ACQ 1, 2), two database servers (DB 1, 2), two storage servers (LTA, network attached storage-NAS), one backup server (DLT) totally 8 servers were installed. SNUH has 11 CRs, 4 CTs, 3 MRIs, 9 NMs, 4 RFs, 20 USs, 7 ESs, 4 SCs, 5 XAs, and 5 Film Ditigers. All these modalities were integrated with PACS. DICOM 3.0 standard was conformed for images. DICOM Gateways were installed for modalities that do not support DICOM. The doctor can query and view Endoscopes, pathologic and anatomic data as well as radiological data. All the past five years exams is accessed less than 10 Seconds via on-line. Through the cooperation with SNUH and Marotech, HIS and PACS work together in stable state. These systems were integrated with HL7 standards and IHE.
Archive and Database
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PACS archive upgrade and data migration: clinical experiences
Brent J. Liu, Luis Documet, Dennis A. Sarti, et al.
Saint John's Health Center PACS data volumes have increased dramatically since the hospital became filmless in April of 1999. This is due in part of continuous image accumulation, and the integration of a new multi-slice detector CT scanner into PACS. The original PACS archive would not be able to handle the distribution and archiving load and capacity in the near future. Furthermore, there is no secondary copy backup of all the archived PACS image data for disaster recovery purposes. The purpose of this paper is to present a clinical and technical process template to upgrade and expand the PACS archive, migrate existing PACs image data to the new archive, and provide a back-up and disaster recovery function not currently available. Discussion of the technical and clinical pitfalls and challenges involved in this process will be presented as well. The server hardware configuration was upgraded and a secondary backup implemented for disaster recovery. The upgrade includes new software versions, database reconfiguration, and installation of a new tape jukebox to replace the current MOD jukebox. Upon completion, all PACS image data from the original MOD jukebox was migrated to the new tape jukebox and verified. The migration was performed during clinical operation continuously in the background. Once the data migration was completed the MOD jukebox was removed. All newly acquired PACS exams are now archived to the new tape jukebox. All PACs image data residing on the original MOD jukebox have been successfully migrated into the new archive. In addition, a secondary backup of all PACS image data has been implemented for disaster recovery and has been verified using disaster scenario testing. No PACS image data was lost during the entire process and there was very little clinical impact during the entire upgrade and data migration. Some of the pitfalls and challenges during this upgrade process included hardware reconfiguration for the original archive server, clinical downtime involved with the upgrade, and data migration planning to minimize impact on clinical workflow. The impact was minimized with a downtime contingency plan.
Fault-tolerant back-up archive using an ASP model for disaster recovery
Brent J. Liu, H. K. Huang, Fei Cao, et al.
A single point of failure in PACS during a disaster scenario is the main archive storage and server. When a major disaster occurs, it is possible to lose an entire hospital's PACS data. Few current PACS archives feature disaster recovery, but the design is limited at best. These drawbacks include the frequency with which the back-up is physically removed to an offsite facility, the operational costs associated to maintain the back-up, the ease-of-use to perform the backup consistently and efficiently, and the ease-of-use to perform the PACS image data recovery. This paper describes a novel approach towards a fault-tolerant solution for disaster recovery of short-term PACS image data using an Application Service Provider model for service. The ASP back-up archive provides instantaneous, automatic backup of acquired PACS image data and instantaneous recovery of stored PACS image data all at a low operational cost. A back-up archive server and RAID storage device is implemented offsite from the main PACS archive location. In the example of this particular hospital, it was determined that at least 2 months worth of PACS image exams were needed for back-up. Clinical data from a hospital PACS is sent to this ASP storage server in parallel to the exams being archived in the main server. A disaster scenario was simulated and the PACS exams were sent from the offsite ASP storage server back to the hospital PACS. Initially, connectivity between the main archive and the ASP storage server is established via a T-1 connection. In the future, other more cost-effective means of connectivity will be researched such as the Internet 2. A disaster scenario was initiated and the disaster recovery process using the ASP back-up archive server was success in repopulating the clinical PACS within a short period of time. The ASP back-up archive was able to recover two months of PACS image data for comparison studies with no complex operational procedures. Furthermore, no image data loss was encountered during the recovery.
Efficient storage and management of radiographic images using a novel wavelet based multiscale vector quantizer
Due to the huge volumes of radiographic images to be managed in hospitals, efficient compression techniques yielding no perceptual loss in the reconstructed images are becoming a requirement in the storage and management of such datasets. A wavelet-based multi-scale vector quantization scheme that generates a global codebook for efficient storage and transmission of medical images is presented in this paper. The results obtained show that even at low bit rates one is able to obtain reconstructed images with perceptual quality higher than that of the state-of-the-art scalar quantization method, the set partitioning in hierarchical trees.
Method of content-based image retrieval for a spinal x-ray image database
Daniel M. Krainak, L. Rodney Long, George R. Thoma
The Lister Hill National Center for Biomedical Communications, a research and development division of the National Library of Medicine (NLM) maintains a digital archive of 17,000 cervical and lumbar spine images collected in the second National Health and Nutrition Examination Survey (NHANES II) conducted by the National Center for Health Statistics (NCHS). Classification of the images for the osteoarthritis research community has been a long-standing goal of researchers at the NLM, collaborators at NCHS, and the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), and capability to retrieve images based on geometric characteristics of the vertebral bodies is of interest to the vertebral morphometry community. Automated or computer-assisted classification and retrieval methods are highly desirable to offset the high cost of manual classification and manipulation by medical experts. We implemented a prototype system for a database of 118 spine x-rays and health survey text data related to these x-rays. The system supports conventional text retrieval, as well as retrieval based on shape similarity to a user-supplied vertebral image or sketch.
Brain imaging registry for neurologic diagnosis and research
Kent Soo Hoo Jr., Stephen T. C. Wong, Robert C. Knowlton, et al.
The purpose of this paper is to demonstrate the importance of building a brain imaging registry (BIR) on top of existing medical information systems including Picture Archiving Communication Systems (PACS) environment. We describe the design framework for a cluster of data marts whose purpose is to provide clinicians and researchers efficient access to a large volume of raw and processed patient images and associated data originating from multiple operational systems over time and spread out across different hospital departments and laboratories. The framework is designed using object-oriented analysis and design methodology. The BIR data marts each contain complete image and textual data relating to patients with a particular disease.
Content based retrieval of lesioned brain images
Stephen Batty, Ann Blandford, John Clark, et al.
HI-PACS enable more efficient data-management leading to increased operating efficiency and therefore better patient care, a content based pet image retrieval system would contribute to the development of a HI-PACS. A database of PET neuro-images has been created with a facility for retrieving via visual content. The adaptation of algorithms developed for alternate imaging modalities (eg-MRI) formed the basis of feature detection and measurement algorithms. The application of these algorithms to greyscale PET images results in data that is employed as database indices and similarity metrics. The feature detection and measurement algorithms can be split into two different methods. The first uses the extracted ideal mid sagittal symmetry line to detect differences between the two hemisphere of the brain, while the second utilizes Gabor filters to measure the texture of the whole brain.
PACS Special Topics
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Protecting regions of interest in medical images in a lossy packet network
Toby Wu, Agnieszka C. Miguel, Eve A. Riskin, et al.
We present two methods for protecting a region of interest (ROI) in a compressed medical image transmitted across a lossy packet network such as the Internet or a wireless channel. We begin with a high quality wavelet-based coder, the Set Partitioning in Hierarchical Trees (SPIHT) algorithm, which orders data progressively by coding the globally important information first. We then compress the ROI to a higher quality than the rest of the image by scaling the wavelet coefficients corresponding to the ROI. This approach moves ROI information earlier in the bit stream. Finally, we add more redundancy to the ROI than to the rest of the image by two techniques. With MD-SPIHT, we repeat wavelet coefficient trees corresponding to the ROI and code them to higher bit rates than the background trees. With ULP-FEC, we use forward error correction (FEC) in an unequal loss protection framework. We find that both methods increase the probability of receiving high quality ROI in the presence of packet loss.
XML-based scripting of multi-modality image presentations in multidisciplinary clinical conferences
Osman M. Ratib, Vivekanand Allada M.D., Magdalena Dahlbom, et al.
We developed a multi-modality image presentation software for display and analysis of images and related data from different imaging modalities. The software is part of a cardiac image review and presentation platform that supports integration of digital images and data from digital and analog media such as videotapes, analog x-ray films and 35 mm cine films. The software supports standard DICOM image files as well as AVI and PDF data formats. The system is integrated in a digital conferencing room that includes projections of digital and analog sources, remote videoconferencing capabilities, and an electronic whiteboard. The goal of this pilot project is to: 1) develop a new paradigm for image and data management for presentation in a clinically meaningful sequence adapted to case-specific scenarios, 2) design and implement a multi-modality review and conferencing workstation using component technology and customizable 'plug-in' architecture to support complex review and diagnostic tasks applicable to all cardiac imaging modalities and 3) develop an XML-based scripting model of image and data presentation for clinical review and decision making during routine clinical tasks and multidisciplinary clinical conferences.
Two year experience with Web connectivity to PACS at a community-based hospital
Brian D. Wadley, Ulrike Hayward, Michael Trambert M.D., et al.
Referring physician web based access to a PACS is evaluated at a community-based hospital. Survey results show 100% perceived improvement in referring physician productivity, and 97% perceived improvement in patient care. Overall satisfaction and perception of ease of use is greater than 90%.Web connectivity to PACS is perceived by 97% to result in decreased visits and calls to the radiology department due to the availability of virtual results, with high value placed on the voice clip summary results by 94% of respondents (the voice clip is a recording made by the radiologist at the time of reading the exam, which summarizes the results of the study).The availability of exams and virtual results via web-based connectivity is perceived to result in increase referrals by 58% of respondents. Web log audit trails are analyzed to evaluate the use of the system by referring physicians. The gross number of cases retrieved over the web for a two-week period is assessed. The number of times a voice clip was played is also evaluated. The results overall show a very positive experience with web connectivity to PACS.
Workflow
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DICOM and imaging informatics-based radiation therapy (RT) server
Maria Y. Y. Law, H. K. Huang, Xiaoyan Zhang, et al.
Radiation therapy (RT) is an image intensive treatment. It requires images from projection X-rays, CT, MR, PET for tumor localization, treatment planning and verification of treatment plans. It also needs patient information, images and their processing for tumor localization and dose computation to ensure the delivery of uniform high dose to the target but avoidance of sensitive structures. In these processes, PACS and imaging informatics technologies are used extensively. However, they are not integrated with these technologies as a complete radiation treatment system. Currently RT treatment still relies mostly on tedious manual image and data transfer methods because the community as a whole has not championed the concept of system integration heavily. System integration of RT treatment has many benefits including lower equipment and operation costs, streamline treatment procedures, and better healthcare delivery to the patient. In this paper, we discuss the concept of a DICOM and imaging informatics-based RT server as an attempt to integrate diverse healthcare information systems, imaging modalities and RT equipment into one seamless treatment system.
Financial and workflow analysis of radiology reporting processes in the planning phase of implementation of a speech recognition system
Tom Whang, Osman M. Ratib, Kathleen Umamoto, et al.
The goal of this study is to determine the financial value and workflow improvements achievable by replacing traditional transcription services with a speech recognition system in a large, university hospital setting. Workflow metrics were measured at two hospitals, one of which exclusively uses a transcription service (UCLA Medical Center), and the other which exclusively uses speech recognition (West Los Angeles VA Hospital). Workflow metrics include time spent per report (the sum of time spent interpreting, dictating, reviewing, and editing), transcription turnaround, and total report turnaround. Compared to traditional transcription, speech recognition resulted in radiologists spending 13-32% more time per report, but it also resulted in reduction of report turnaround time by 22-62% and reduction of marginal cost per report by 94%. The model developed here helps justify the introduction of a speech recognition system by showing that the benefits of reduced operating costs and decreased turnaround time outweigh the cost of increased time spent per report. Whether the ultimate goal is to achieve a financial objective or to improve operational efficiency, it is important to conduct a thorough analysis of workflow before implementation.
New trends in radiology workstation design
In the radiology workstation design, the race for adding more features is now morphing into an iterative user centric design with the focus on ergonomics and usability. The extent of the list of features for the radiology workstation used to be one of the most significant factors for a Picture Archiving and Communication System (PACS) vendor's ability to sell the radiology workstation. Not anymore is now very much the same between the major players in the PACS market. How these features work together distinguishes different radiology workstations. Integration (with the PACS/Radiology Information System (RIS) systems, with the 3D tool, Reporting Tool etc.), usability (user specific preferences, advanced display protocols, smart activation of tools etc.) and efficiency (what is the output a radiologist can generate with the workstation) are now core factors for selecting a workstation. This paper discusses these new trends in radiology workstation design. We demonstrate the importance of the interaction between the PACS vendor (software engineers) and the customer (radiologists) during the radiology workstation design. We focus on iterative aspects of the workstation development, such as the presentation of early prototypes to as many representative users as possible during the software development cycle and present the results of a survey of 8 radiologists on designing a radiology workstation.
Radiography for intensive care: participatory process analysis in a PACS equipped and film/screen environment
Regina Peer, Siegfried Peer, Heike Sander, et al.
If new technology is introduced into medical practice it must prove to make a difference. However traditional approaches of outcome analysis failed to show a direct benefit of PACS on patient care and economical benefits are still in debate. A participatory process analysis was performed to compare workflow in a film based hospital and a PACS environment. This included direct observation of work processes, interview of involved staff, structural analysis and discussion of observations with staff members. After definition of common structures strong and weak workflow steps were evaluated. With a common workflow structure in both hospitals, benefits of PACS were revealed in workflow steps related to image reporting with simultaneous image access for ICU-physicians and radiologists, archiving of images as well as image and report distribution. However PACS alone is not able to cover the complete process of 'radiography for intensive care' from ordering of an image till provision of the final product equals image + report. Interference of electronic workflow with analogue process steps such as paper based ordering reduces the potential benefits of PACS. In this regard workflow modeling proved to be very helpful for the evaluation of complex work processes linking radiology and the ICU.
Workflow oriented hanging protocols for radiology workstation
The goal is to provide a smooth, efficient and automatic display for interpretation of medical images by using a new generation of hanging protocols (HPs). HPs refer to a set of rules defining the way images are arranged on the computer screen immediately after opening a case. HPs usually include information regarding placement of the sequences, viewing mode, layout, window width and level (W/L) settings, zoom and pan. We present the results of a survey of 8 radiologists on (1) the necessity of using HPs, (2) the applicability of a hierarchical organization of HPs and (3) the number of HPs required for interpretation. We discuss some limitations and challenges associated with the HP including automatic placement of the series on the screen despite non-standard series labeling, generation of pseudo-series, creation of the 'study context' and identification of relevant priors, and image display standardization with automatic orientation and shuttering. The paper also addresses the HP selection based on the workstation's hardware such as number and type of monitors, size of the study, and presence of image processing routines tailored to the information needs and level of expertise of particular users. Our 'heads-up' approach is meant to free the user's conscious processing for reasoning such as detection of patterns so allowing for the execution of the tasks in an efficient, yet highly adaptive manner, sensitive to shifting concepts. Automation of routine tasks is maximized through the creation of shortcuts and macros embedded in features like multi-stage HP.
System integration evaluation: a testing approach for new implemented systems
After implementation of an integrated healthcare solution (HIS/RIS/PACS), buyers need assurance that they are receiving what was promised. After a system was installed, the buyer creates a list of improvements to address areas where final satisfaction is pending. The following approach shall help testing unclear system specification or missed features. The requirements related to technology address hard-/software dependencies, uptime or single point of failure. It lists features, programming languages and operating systems. It addresses interfaces and protocols between system components, performance and security requirements. The requirements related to data define the workload between image sources and sinks. At the sources, the data type and information content can be described in detail. The requirement of image accessibility relates to automation supporting prior images and rule based image distribution of images. The requirements related to workflow refer to the display and post processing options that are related to image working places. The reporting support requirements refer to a classification of data that is sent into the system and needs to be tracked to avoid duplicate work or support change in access criteria for images.
Connectivity
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Error component analysis for PACS: operational sources of data error in real world PACS for DICOM series, study, and patient level identifiers
Richard L. Kennedy, James Anthony Seibert
The gold standard for modern PACS workflow is now considered to be a complete integration of HIS, RIS and PACS datastreams. However, a number of current obstacles exist in regard to achieving this level of integration in real-world practice environments, given the current level of modality support for more advanced DICOM services such as MWL, MPPS, and Storage Commitment. In this paper, many of the more common sources of disparity between HIS/RIS and PACS data are discussed, as well as possible DICOM-based mitigations and possible PACS workflow models not requiring modality upgrades. These are discussed in the context of the IHE model, and compared to the ideal of complete IHE workflow. Various operational sources of modality-based patient demographic data for existing PACS are discussed and analyzed from a DICOM perspective, comparing modality inputs for a typical large PACS to RIS data references. Disparities between PACS and RIS data are emphasized, with the goal of PACS/RIS data reconciliation. The existing obstacles to this integration are discussed, and the application of DICOM Modality Worklist, Storage Commitment, and Performed Procedure Step Services are discussed in reference to these error sources. As the subject site utilizes DICOM Modality Worklist, those operational sources of error that remain after Modality Worklist was implemented are analyzed in the context of the existing modality workflow limitations. The intrinsic disparity between CPT-based billing and reporting structures and existing DICOM modality models for CT, MR, US, R&F, and CR are discussed, and examples given for operational challenges in integrating these elements using existing modality design. Conclusions included that the Modality Worklist, in itself, is inadequate to drive RIS-integrated PACS workflow, and that current modality limitations preclude complete PACS/RIS datastream integration at this time. Several alternative mitigation models are discussed using existing modalities, as well as suggestions for improvements in modality workflow design.
CIAS: achieving interoperability using CORBA
Ramon Alfredo Moreno, Vivian Rodrigues Fiales, Sergio Shiguemi Furuie
This paper presents one of the efforts of the Heart Institute of Sao Paulo for the development of a distributed system for retrieving and research of medical images and medical information. The objective is the implementation of an open architecture based on the Clinical Image Access Service (CIAS) specification, defined by Object Management Group, which allows the recover of meta-data and relevant information for general practitioners and clinical specialists in a multi-platform, distributed environment. The CIAS-InCor was developed in Java language, to achieve multi-platform capability, together with CORBA. The images are received in DICOM format, being stored into relational database for the recover of meta-information through the CIAS specification. A prototype of a CIAS server and client were designed and implemented. It has been possible to recover images and clinical information from the CIAS server in a distributed, non-homogenous environment with success. Through the use of standards and new technologies the Heart Institute of Sao Paulo is reaching a high level of integration between systems and equipments and going towards the development of a complete electronic medical record. The CIAS is still an unfinished specification with good points like interoperability and weaknesses like the lack of semantics between exchanged data.
Integrated radiologist's workstation enabling the radiologist as an effective clinical consultant
Kevin W. McEnery, Charles T. Suitor, Stan Hildebrand, et al.
Since February 2000, radiologists at the M. D. Anderson Cancer Center have accessed clinical information through an internally developed radiologist's clinical interpretation workstation called RadStation. This project provides a fully integrated digital dictation workstation with clinical data review. RadStation enables the radiologist as an effective clinical consultant with access to pertinent sources of clinical information at the time of dictation. Data sources not only include prior radiology reports from the radiology information system (RIS) but access to pathology data, laboratory data, history and physicals, clinic notes, and operative reports. With integrated clinical information access, a radiologists's interpretation not only comments on morphologic findings but also can enable evaluation of study findings in the context of pertinent clinical presentation and history. Image access is enabled through the integration of an enterprise image archive (Stentor, San Francisco). Database integration is achieved by a combination of real time HL7 messaging and queries to SQL-based legacy databases. A three-tier system architecture accommodates expanding access to additional databases including real-time patient schedule as well as patient medications and allergies.
DICOM
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Extending DICOM imaging to new clinical specialties in the healthcare enterprise
Peter M. Kuzmak, Ruth E. Dayhoff M.D.
DICOM is a success for radiology and cardiology and it is now starting to be used for the other clinical specialties. The US Department of Veterans Affairs has been instrumental in promoting this advancement. We have worked with a number of non-radiology clinical speciality imaging vendors over the past two years, encouraging them to support DICOM, providing requirement specifications. Validating their implementations, using their products, and integrating their systems with the VA healthcare enterprise. We require each new clinical speciality vendor to support the DICOM Modality Worklist and Storage services and insist that they perform validation testing with us over the Internet. Two years ago we began working with two commercial DICOM image acquisition applications in ophthalmology and endoscopy. We are now dealing with over a dozen: five in ophthalmology, two in endoscopy, and six in dental. This has been a very productive endeavor. Because mature software development toolkits now exist, the vendors can quickly integrate DICOM with their existing imaging products. Each of the dental vendors, for example, was able to accomplish this task in less than three months. Getting the imaging modality vendors to support DICOM is only part of the story, however. We are also working on getting the VistA hospital information system to properly handle DICOM interfaces to various clinical specialties. This has been more difficult than expected because the workflow in clinical specialties is much more varied than that in radiology. This required us to develop software that is much more flexible than that used for radiology. Fortunately, the standard DICOM Modality Worklist and Storage services can be used without change. In addition to a more variable workflow, the use of structured reporting is much more advanced in clinical specialties than in radiology, and significant work is needed to define templates and communicate this data using DICOM. Since some speciality modules of our hospital information system currently store only report text, we also have to figure out how to store and display the discrete structured report data. The work involved in extending DICOM to the clinical specialties, and in integrating them with the hospital information system is an ongoing and worthwhile challenge. Our goal is to incorporate al of the patient's data into the electronic record, and DICOM is making this easier for everyone. Considerable investment, however, has to be made in the hospital information system software to accrue the full benefit.
Building a gateway with open source software for secure-DICOM communication over insecure networks
Dirk Emmel, Jens Ricke, Lutz Stohlmann, et al.
For Teleradiology the exchange of DICOM-images is needed for several purposes. Existing solutions often don't consider about the needs for data security and data privacy. Communication is done without any encryption over insecure networks or with encryption using proprietary solutions, which reduces the data communication possibilities to partners with the same equipment. Our goal was to build a gateway, which offers a transparent solution for secure DICOM-communication in a heterogeneous environment We developed a PC-based gateway system with DICOM-communication to the in-house network and secure DICOM communication for the communication over the insecure network. One gateway installed at each location is responsible for encryption/decryption. The sender just transfers the image data over the DICOM protocol to the local gateway. The gateway forwards the data to the gateway on the destination site using the secure DICOM protocol, which is part of the DICOM standard. The receiving gateway forwards the image data to the final destination again using the DICOM-Protocol. The gateway is based on Open Source software and runs under several operating systems. Our experience shows a reliable solution, which solves security issues for DICOM communication of image data and integrates seamless into a heterogeneous DICOM environment.
Computer supported approach for an interoperability assessment of DICOM implementations
Marco Eichelberg, Joerg Riesmeier, Peter F. Jensch
The DICOM standard has established itself successfully in the PACS world. Practice has shown, however, that interoperability of DICOM devices cannot be taken for granted. Many devices only support a subset of the capabilities and options of the DICOM services they claim to support - and even that sometimes in a non-conforming manner. This issue is only partly addressed by the concept of the DICOM conformance statement which describes the services, options and features supported by an implementation and allows an expert to assess whether two DICOM implementations are likely to interoperate. We propose a new approach that can be understood as a step towards an 'automated' conformance statement. The 'Description Notation' for Interoperability Assessment' (DeNIA) allows to formally describe the data structures sent or received by a DICOM implementation. An evaluation tool reads two of these models and automatically derives a conclusion whether or not the two systems can successfully exchange messages and whether all messages created by the sender can be understood by the receiver. DeNIA allows to explicitly describe the capability of a receiver to 'gracefully' accept certain deviations from the standard -- a capability which accounts for much of the interoperability found in DICOM systems today.
Design and implementation of a robust high-availability DICOM print network in a large multimodality clinical environment
S. Jeff Shepard, Stephen K. Thompson, Kerry T. Krugh, et al.
This work will describe the implementation of a highly reliable DICOM print network at our institution. The system was designed to provide DICOM print services to many modalities, allowing customized LUT assignments either by calling AET or by special request from the modality. The system was implemented on a small scale with hardware from three different manufacturers (Agfa/Sterling, Kodak, and Fuji) for evaluation purposes. Our experiences with each system will be presented. The final configuration (Fuji PS551/DPL) was scaled up to meet the needs for hard copy production in our busy (300,000 exams/year) clinical operation. Quality control is accomplished via automatic (chron job) initiation of DICOM print jobs from a Unix-based workstation or by manual initiation from one of several PC's utilizing e-Film'sTM DICOM print capabilities. Print servers are connected to multiple printers and are configured for automatic fail-over on printer error detection. Modalities are configured with dual ('Primary' and 'Secondary') print destinations to allow manual redirection of print activity on print server error detection. As a result, the system provides an extremely high level of dependability. The printers also sort by AET so that the output from any given modality may be directed to a specific sorting bin, significantly reducing the effort needed to sort films and match with paperwork prior to hanging.
Authentication, integrity, and confidentiality in DICOM structured reporting: concept and implementation
Joerg Riesmeier, Marco Eichelberg, Klaus Kleber, et al.
With the release of 'DICOM Structured Reporting' (SR) as an official extension of the standard about two years ago, DICOM has entered a new domain that is only indirectly related to medical imaging. Basically, DICOM SR is a general model allowing to encode medical reports in a structured manner in DICOM's tag-based format. Therefore, the existing DICOM infrastructure can be used to archive and communicate structured reports, with only relatively small changes to existing systems. As a consequence of the introduction of medical reports in a digital form, the relevance of security measures increases significantly. We have developed a prototype implementation of DICOM structured reporting together with the new security extensions for secure transport connections and digital signatures. The application allows to create, read and modify any SR document, to digitally sign an SR document in whole or part and to transmit such documents over a network. While the secure transport connection protects data from modifications or unauthorized access only during transmission, digital signatures provide a lifetime integrity check and, therefore, maintain the legal document status of structured reports. The application has been successfully demonstrated at RSNA 2000 and ECR 2001, and is freely available on the Internet.
Quality of DICOM header information for image categorization
The widely used DICOM 3.0 imaging protocol specifies optional tags to store specific information on modality and body region within the header: Body Part Examined and Anatomic Structure. We investigate whether this information can be used for the automated categorization of medical images, as this is an important first step for medical image retrieval. Our survey examines the headers generated by four digital image modalities (2 CTs, 2 MRIs) in clinical routine at the Aachen University Hospital within a period of four months. The manufacturing dates of the modalities range from 1995 to 1999, with software revisions from 1999 and 2000. Only one modality sets the DICOM tag Body Part Examined. 90 out of 580 images (15.5%) contained false tag entries causing a wrong categorization. This result was verified during a second evaluation period of one month one year later (562 images, 15.3% error rate). The main reason is the dependency of the tag on the examination protocol of the modality, which controls all relevant parameters of the imaging process. In routine, the clinical personnel often applies an examination protocol outside its normal context to improve the imaging quality. This is, however, done without manually adjusting the categorization specific tag values. The values specified by DICOM for the tag Body Part Examined are insufficient to encode the anatomic region precisely. Thus, an automated categorization relying on DICOM tags alone is impossible.
PACS and electronic health records
Simona Cohen, Flora Gilboa, Uri Shani
Electronic Health Record (EHR) is a major component of the health informatics domain. An important part of the EHR is the medical images obtained over a patient's lifetime and stored in diverse PACS. The vision presented in this paper is that future medical information systems will convert data from various medical sources -- including diverse modalities, PACS, HIS, CIS, RIS, and proprietary systems -- to HL7 standard XML documents. Then, the various documents are indexed and compiled to EHRs, upon which complex queries can be posed. We describe the conversion of data retrieved from PACS systems through DICOM to HL7 standard XML documents. This enables the EHR system to answer queries such as 'Get all chest images of patients at the age of 20-30, that have blood type 'A' and are allergic to pine trees', which a single PACS cannot answer. The integration of data from multiple sources makes our approach capable of delivering such answers. It enables the correlation of medical, demographic, clinical, and even genetic information. In addition, by fully indexing all the tagged data in DICOM objects, it becomes possible to offer access to huge amounts of valuable data, which can be better exploited in the specific radiology domain.
Practical approach to store DICOM-conform presentations of radiological images
Lutz Vorwerk, Christoph Meinel
Engrane is a system which is used to prepare and show presentations of radiological images as well as the reports which belong to these images. The presentations with Engrane will be performed by displaying DICOM (digital imaging and communication in medicine) images and an interpretation of the images presented as text. A database is used to manage DICOM-objects like images and reports. Images are transferred using the DICOM protocol enhanced by TLS (transport layer security) protocol. Correlating images and reports is necessary as well as a log mechanism which is used to reconstruct a presentation. The correlation and the log mechanism lead to SR (structured reporting). An order is needed for sequences of elements. A new supplement called 'hanging protocol' define arrangements of elements. It has to be examined if SR or 'handing protocol' is sufficient in order to store presentation files of radiological images. Neither SR nor 'hanging protocols' fulfill all requirements. Engrane was developed in order to improve the presentation and the communication of radiological images. An appropriate standard to store those presentations has to be defined. Therefore, we suppose a combination of hanging protocols and SR in order to meet technical and organizational requirements.
JJ1017 image examination order codes: standardized codes supplementary to DICOM for imaging modality, region, and direction
Michio Kimura, Makoto Kuranishi, Yoshiharu Sukenobu, et al.
The DICOM standard includes non-image data information such as image study ordering data and performed procedure data, which are used for sharing information between HIS/RIS/PACS/modalities, which is essential for IHE. In order to bring such parts of the DICOM standard into force in Japan, a joint committee of JIRA and JAHIS (vendor associations) established JJ1017 management guideline. It specifies, for example, which items are legally required in Japan while remaining optional in the DICOM standard. Then, what should be used for the examination type, regional, and directional codes? Our investigation revealed that DICOM tables do not include items that are sufficiently detailed for use in Japan. This is because radiology departments (radiologists) in the US exercise greater discretion in image examination than in Japan, and the contents of orders from requesting physicians do not include the extra details used in Japan. Therefore, we have generated the JJ1017 code for these 3 codes for use based on the JJ1017 guidelines. The stem part of the JJ1017 code partially employs the DICOM codes in order to remain in line with the DICOM standard. JJ1017 codes are to be included not only in IHE-J specifications, also in Ministry recommendations of health data exchange.
Security/Fault Tolerance
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Fault-tolerant PACS server
Fei Cao, Brent J. Liu, H. K. Huang, et al.
Failure of a PACS archive server could cripple an entire PACS operation. Last year we demonstrated that it was possible to design a fault-tolerant (FT) server with 99.999% uptime. The FT design was based on a triple modular redundancy with a simple majority vote to automatically detect and mask a faulty module. The purpose of this presentation is to report on its continuous developments in integrating with external mass storage devices, and to delineate laboratory failover experiments. An FT PACS Simulator with generic PACS software has been used in the experiment. To simulate a PACS clinical operation, image examinations are transmitted continuously from the modality simulator to the DICOM gateway and then to the FT PACS server and workstations. The hardware failures in network, FT server module, disk, RAID, and DLT are manually induced to observe the failover recovery of the FT PACS to resume its normal data flow. We then test and evaluate the FT PACS server in its reliability, functionality, and performance.
Managed PACS operation with an automatic monitoring tool
Jianguo Zhang, Ruolin Han, Dongqing Wu, et al.
Huadong hospital in Shanghai with 800 beds provides health care services for inpatients and outpatients, as well as special senior and VIP patients. In order to move to digital imaging based radiology practice, and also provide better intra-hospital consultation services for senior and VIP patients, we started to implement PACS for hospital wide services from 1999, and also designed and developed an automatic monitoring system (AMS) to monitor and control PACS operation and dataflow to decrease the total cost of ownership for PACS operation. We installed the AMS on top of the Huadong Hospital PACS in the May of 2001. The installation was painless, did not interrupt the normal PACS operation, and took only one month. The PACS administrators with the AMS can now monitor and control the entire PACS operation in real time, and also track patient and image data flow automatically. These features make administrators take proper action even before user's complaint if any failure happened in any PACS component or process, they reduce the size of the management team, and decrease total cost of PACS ownership.
Secure web-based access to radiology: forms and databases for fast queries
Roderick W. McColl, Thomas J. Lane
Currently, Web-based access to mini-PACS or similar databases commonly utilizes either JavaScript, Java applets or ActiveX controls. Many sites do not permit applets or controls or other binary objects for fear of viruses or worms sent by malicious users. In addition, the typical CGI query mechanism requires several parameters to be sent with the http GET/POST request, which may identify the patient in some way; this in unacceptable for privacy protection. Also unacceptable are pages produced by server-side scripts which can be cached by the browser, since these may also contain sensitive information. We propose a simple mechanism for access to patient information, including images, which guarantees security of information, makes it impossible to bookmark the page, or to return to the page after some defined length of time. In addition, this mechanism is simple, therefore permitting rapid access without the need to initially download an interface such as an applet or control. In addition to image display, the design of the site allows the user to view and save movies of multi-phasic data, or to construct multi-frame datasets from entire series. These capabilities make the site attractive for research purposes such as teaching file preparation.
Metadata requirements for results of diagnostic imaging procedures: a BIIF profile to support user applications
Nicholas J.G. Brown, David S.L. Lloyd, Melvin I. Reynolds, et al.
A visible digital image is rendered from a set of digital image data. Medical digital image data can be stored as either: (a) pre-rendered format, corresponding to a photographic print, or (b) un-rendered format, corresponding to a photographic negative. The appropriate image data storage format and associated header data (metadata) required by a user of the results of a diagnostic procedure recorded electronically depends on the task(s) to be performed. The DICOM standard provides a rich set of metadata that supports the needs of complex applications. Many end user applications, such as simple report text viewing and display of a selected image, are not so demanding and generic image formats such as JPEG are sometimes used. However, these are lacking some basic identification requirements. In this paper we make specific proposals for minimal extensions to generic image metadata of value in various domains, which enable safe use in the case of two simple healthcare end user scenarios: (a) viewing of text and a selected JPEG image activated by a hyperlink and (b) viewing of one or more JPEG images together with superimposed text and graphics annotation using a file specified by a profile of the ISO/IEC Basic Image Interchange Format (BIIF).
Poster Session
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Automatic monitoring system for PACS management and operation
Jianguo Zhang, Ruolin Han, Dongqing Wu, et al.
In order to achieve the high and continuous availability in PACS operation, the PACS component status would be monitored seriously and quick responds would apply to the component if any failure happened to any PACS key component either in hardware or software level. In order to protect the data loss and also for security issue, the PACS data flow, e.g., from acquisition to final display, would be tracked carefully. All these measures will increase the total cost of ownership (TCO). We built an automatic monitoring system (AMS) on top of the PACS to assist the PACS management and to make the PACS component status and internal data flow more transparent to the administrators. The PACS AMS consists of two parts: monitoring agents running in each PACS component computer and a Monitor Server running in a remote computer. Monitoring agents are connected to all PACS processes running in each PACS component. The Monitor Server monitors each agent that allows the server to track the status of individual PACS process. The PACS managers can now monitor and control the entire PACS operation in real time, and also track patient and image data flow automatically.
Time analysis for optimization of radiology workflow in conventional radiology during RIS-PACS-integration
Peter Falkensammer, Peter I. Soegner M.D., Dieter zur Nedden
The integration of RIS-PACS systems in radiology units are intended to reduce time consumption in radiology workflow and thus to increase radiologist productivity. Along with the RIS-PACS integration at the University Hospital Innsbruck we analyzed workflow from patient admission to release of final reports before implementation. The follow up study after six months of the implementation is currently in work. In this study we compared chest to skeletal x-ray examinations in 969 patients before the implementation. Drawing the admission-to-release-of-final-report period showed a two-peak diagram with the first peak corresponding to a release of final results on the same day and the second peak to a release on the following day. In the chest x-ray group, 57% were released the same day (mean value 4:02 hours) and 43% the next day (mean value 21:47 hours). Looking at the skeletal x-rays 40% were released the same day (mean value 3:58 hours) and 60% were released the next day (mean value 21:05 hours). Summarizing the results we should say, that the average chest x-ray requires less time than an skeletal x-ray, due to the fact that a greater percentage of reports is released the same day. The most important result is, that the most time consuming workstep is the exchange of data media between radiologist and secretary with at least 5 hours.
Integrating a DICOM acquisition and distribution gateway for micro-CT imaging in a PACS environment
Jun Zhuang, Dongqing Wu, Wei Xie, et al.
A dedicated small animal x-ray computed tomography system, named MicroCT, has been developed to mutagenize small animals such as mice for anatomical phenotypes in vivo. However, its output volumes are very large, and it is a tough job to transfer, archive and mange them in order. We designed a DICOM standard conformance image acquisition gateway (IAG) to interface the MicroCT system with PACS. The IAG consists of 4 major modules. First module detects the output of MicroCT in shared disk, and offers a GUI for user to modify or add information relative to imaging. Second module is DICOM encoding process, which creates DICOM objects, fills the DICOM header structure with information both from log files and manual settings, and converts raw image data to DICOM format. Third module is for local image management, which consists of an image database and a management tool. The last module is a communication process working as DICOM Storage SCU (Service Class User) to send encoded DICOM images to remote PACS computers or DICOM conformance viewers for display or image management. Using the developed acquisition gateway can integrate MicroCT imaging system into a PACS infrastructure, and enable potential users to obtain benefits from matured PACS technologies.
Automated creation of radiology teaching modules: demonstration of PACS integration and distribution
Bhargav Raman, Raghav Raman, Lalithakala Raman, et al.
The creation of radiology teaching modules has historically required manual offline authoring. Our system can integrate with commercial PACS to allow clinicians to author teaching modules at their clinical PACS workstations without further manual input. Our system provides a DICOM interface and an automated teaching file database. We tested our system with the PACS deployed at our institution (GE Medical Systems, Milwaukee, WI). We used a networked Windows workstation (Microsoft, Redmond, WA) running SQL Server 2000, registered on our PACS system as a DICOM receiver. Teaching files were created at clinical workstations and any desired annotation and cataloguing instructions were added using standard annotation tools. The files were pushed using DICOM network transfer. Anonymizing, annotation and cataloguing were done automatically using DICOM header information. Additional information from our HIS/RIS system was transmitted using private DICOM header fields. Teaching files were then added to the web - accessible teaching module database. We present a system that integrates the creation of teaching files into the daily clinical workflow, allowing clinicians to immediately publish interesting cases from their clinical workstation. Our system uses standard protocols and requires minimal configuration to integrate with existing PACS systems, enabling a low-cost, expandable and vendor independent solution.
XML&CORBA-based distributed system for information integration and dissemination in multimedia neuroimaging applications
Medical information systems based in different hospital departments face tremendous difficulty in information exchange and dissemination due to the multitudes of hardware and software platforms running these systems. In this paper, we describe a distributed information system for integrating various hospital systems in supporting clinical neuroimaging research and epilepsy surgical planning. Our distributed information system uses a three-tiered architecture consists of a user-interface tier, application logic tier and data store tier. Two system implementations based on this software architecture but using different integration technologies were developed and are discussed in this paper: the XML (extensible Mark Up Language)-based implementation and the CORBA (Common Object Request Broker Architecture)-based implementation. In the XML-based implementation, application logic tier communicates with user-interface tier and data store tier using HTTP and XML for data exchange. For the data exchange in CORBA-based implementation, the middleware uses IIOP (Internet inter-ORB protocol) to call CORBA objects in the data store tier then to return the results to the user-interface tier. For the user-interface tier of either implementation, the Web browsers are served as clients to invoke application components or agents in the middleware. The application of the proposed distributed system allows clinical users to access, search and retrieve the multimedia information in any underlying computer systems with commonly used Web browsers. Preliminary results show that the system is effective for information integration and data sharing among the different departmental systems in the hospital for neuroimaging applications.
Effectiveness of wireless communication using 100-Mbps infrared in PACS
Doo-Hoe Ha, Man-Sik Moon, Dong-Yeol Jang, et al.
In our hospital, two buildings are separated by public road and was communicated each other using 2 Mbps public cable network. Recently inter-building communication with 100 Mbps infrared has been established for PACS. Gigabit network has been established in the main building. To evaluate usefulness of infrared communication, actual data transfer rate was checked. When 2 Mbps public cable was used, actual data transfer rate using 32 Mbytes text file was 193.9 Mbps. After infrared communication was established, effective network speed between two link heads of infrared was 45 Mbps. Actual data transfer rate with 32 Mbytes text file was 4.98 Mbps. Average transfer rates was also checked each 10 times using compressed medical images of each modalities from CR (4 Mbytes), ultrasound (200 Kbytes), CT (250 Kbytes), MRI (77.6 Kbytes) and fluoroscopy (1 Mbytes), and using a raw data of CR (28 Mbytes). Total average transfer rate was 4.91 Mbps. To compare data transfer rate in the separated building with them in the main building, the rate with a 14 Mbytes CR was checked 10 times at the each building. Average data transfer rate was 6.93 Mbps in the main building and 4.05 Mbps in the separated building. In conclusion, when two hospital buildings are separated, an infrared networking can be replaced for fiber-optic cable networking in PACS environment.
IHE year 3 demonstration participation at RSNA 2001: image manager, image archive and MPPS manager
HeeJung Park, HyunWoo Lim, DongOok Kim, et al.
The IHE initiative sponsored by the RSNA and HIMMS defines a Technical Framework designed to advance the state of data integration in a healthcare environment. This Technical framework defines a set of actors and the roles they must perform for each Integration Profile. Each role consists of a well-defined set of electronic transactions that are based on existing healthcare information standards, namely: DICOM and HL7. IHE brings together the major vendors in the healthcare information and imaging systems industry to agree upon and demonstrate standard interfaces and data architectures at the annual meetings of the RSNA and HIMSS since 1999. We have implemented grouping actors, namely Image Manager, Image Archive and MPPS Manager and selected PGP Integration Profile for IHE Year3 Demonstration at the annual meetings of the RSNA 2001 and HIMSS 2002. Storage Service, Query/Retrieve Service, Storage Commitment Service, and Modality Performed Procedure Step Service of DICOM Standard and also A02, A03, A06, A07, A08 and A40 Event of ADT Messages and ORM Message among lots of messages of HL7 Standard in accordance with IHE Technical Framework have developed in our system. We passed vendor interoperability testing at IHE Connectathon on October and demonstrated successfully with other vendors at the IHE Demonstration of RSNA 2001.
DICOM structured report: implementation notes for basic structured reporting system
DongOok Kim, DongHyuk Lee, JinHyung Lee, et al.
Structured Report (SR) is new standard of interchanging diagnostic report between medical devices. SR is encoded as traditional DICOM (Digital Imaging and Communications in Medicine) format. There are two types of SR, which are Basic Text SR and Enhanced SR. Enhanced SR includes more information, such as measurement information, than Basic Text SR. In the system point of view, SR can be classified as Report Creator, Report Repository, Report Manager, Report Reader, External Report Repository Access, and Enterprise Result Repository. Specific system transactions are defined at IHE Year3 Technical Framework (Fig1). This paper is an implementation note for Report Creator and Report Reader of the Basic Text SR. The Report Creator has a tree structure for the user interface. The tree structure is converted to DICOM SR. This DICOM SR can be transferred to Report Manager. Report Reader gets SRs through DICOM SR Query/Retrieve Service. Report Reader saves the SR at local Database. The SR is converted to XML and the XML is combined with XSL to be displayed at the SR Browser. Microsoft Internet Explorer is utilized for the SR Browser.
Design considerations for a multisite POTS-based telemammography system
John Drescher, Glenn S. Maitz, J. Ken Leader III, et al.
As the number of mammographic examinations increases, it becomes clear that in many underserved locations, there is a lack of expertise that is required for consistent, highly accurate, and timely diagnosis. Hence, mammograms are frequently sent to other medical facilities, and a significant fraction of women (typically 3 - 10%) are recalled for additional examinations. It is the purpose of this project to develop, test, and clinically evaluate a telemammography system that will operate between several remote locations and a large breast cancer center. In this manuscript we describe the design considerations, implementation, and initial testing that were undertaken, to date. The system digitizes a mammogram at 50 micrometers pixel size, compresses the resulting image file (approximately 75:1), and transmits it over a telephone line to the central site where the data received are decompressed and displayed on a high-resolution workstation in approximately 4 minutes per image. Initial testing of the system indicates that a relatively inexpensive system for 'almost real-time' telemammography can be employed in any geographic area that possesses standard telephone lines, and this approach to enhance communication may make it possible to offer better mammographic services at remote locations.
Development of quantitative security optimization approach for the picture archives and carrying system between a clinic and a rehabilitation center
Kiyofumi Haneda, Toshio Kajima, Tadashi Koyama, et al.
The target of our study is to analyze the level of necessary security requirements, to search for suitable security measures and to optimize security distribution to every portion of the medical practice. Quantitative expression must be introduced to our study, if possible, to enable simplified follow-up security procedures and easy evaluation of security outcomes or results. Using fault tree analysis (FTA), system analysis showed that system elements subdivided into groups by details result in a much more accurate analysis. Such subdivided composition factors greatly depend on behavior of staff, interactive terminal devices, kinds of services provided, and network routes. Security measures were then implemented based on the analysis results. In conclusion, we identified the methods needed to determine the required level of security and proposed security measures for each medical information system, and the basic events and combinations of events that comprise the threat composition factors. Methods for identifying suitable security measures were found and implemented. Risk factors for each basic event, a number of elements for each composition factor, and potential security measures were found. Methods to optimize the security measures for each medical information system were proposed, developing the most efficient distribution of risk factors for basic events.
Data compression and storage into an EEG multichannel system using wavelets technique
Volodymyr I. Ponomaryov, Leonardo Badillo, Cristina Juarez, et al.
This paper presents the use of Wavelet function technique to compress and storage the EEG signal into a multichannel EEG system. This system consists of such components: multichannel bio-amplify, analog filters, ADC, microprocessor, DSP, PCMCIA memory, etc. The algorithms to compress EEG signal have been implemented using language C/C++. The proposed digital FIR filter to compress the signal has own coefficients chosen as the coefficients of Daubechies Wavelets. The results of experiments with implemented procedures have shown the compression ratio and SNRs values EEG in real time. Different results of the values of time for real compressing and storing are presented for DSP and AMD586 processor used.
vMon-mobile (R) provides wireless connection to the electronic patient record
Pedro P.M. Oliveira Jr., Marina Rebelo, Paulo Eduardo Pilon, et al.
This work presents the development of a set of tools to help doctors to continuously monitor critical patients. Real-time monitoring signals are displayed via a Web Based Electronic Patient Record (Web-EPR) developed at the Heart Institute. Any computer on the Hospital's Intranet can access the Web-EPR that will open a browser plug-in called vMon. Recently vMon was adapted to wireless mobile devices providing the same real-time visualization of vital signals of its desktop counterpart. The monitoring network communicates with the hospital network through a gateway using HL7 messages and has the ability to export waveforms in real time using the multicast protocol through an API library. A dedicated ActiveX component was built that establishes the streaming of the biomedical signals under monitoring and displays them on an Internet Explorer 5.x browser. The mobile version - called vMon-mobile - will parse the browser window and deliver it to a PDA device connected to a local area network. The result is a virtual monitor presenting real-time data on a mobile device. All parameters and signals acquired from the moment the patient is connected to the monitors are stored for a few days. The most clinically relevant information is added to patient's EPR.