Medical imaging is increasing its importance in matters of medical diagnosis and in treatment support. Much is due to computers that have revolutionized medical imaging not only in acquisition process but also in the way it is visualized, stored, exchanged and managed. Picture Archiving and Communication Systems (PACS) is an example of how medical imaging takes advantage of computers. To solve problems of interoperability of PACS and medical imaging equipment, the Digital Imaging and Communications in Medicine (DICOM) standard was defined and widely implemented in current solutions. More recently, the need to exchange medical data between distinct institutions resulted in Integrating the Healthcare Enterprise (IHE) initiative that contains a content profile especially conceived for medical imaging exchange: Cross Enterprise Document Sharing for imaging (XDS-i). Moreover, due to application requirements, many solutions developed private networks to support their services. For instance, some applications support enhanced query and retrieve over DICOM objects metadata.
This paper proposes anintegration framework to medical imaging networks that provides protocols interoperability and data federation services. It is an extensible plugin system that supports standard approaches (DICOM and XDS-I), but is also capable of supporting private protocols. The framework is being used in the Dicoogle Open Source PACS.
Cloud computing; data integration; DICOM; medical imaging; PACS and XDS-I.
With the advent of electronic imaging and the internet, the ability to create, search, access, and archive digital imaging teaching files has dramatically improved. Despite the fact that a picture archival and communication system (PACS) has the potential to greatly simplify the creation of, archival, and access to a department or multifacility teaching file, this potential has not yet been satisfactorily realized in our own and most other PACS installations. Several limitations of the teaching file tools within our PACS have become apparent over time. These have, at our facility, resulted in a substantially reduced role of the teaching file tools for conferences, daily teaching, and research purposes. With the PACS at our institution, academic folders can only be created by the systems engineer, which often serves as an impediment to the teaching process. Once these folders are created, multiple steps are required to identify the appropriate folders, and subsequently save images. Difficulties exist for those attempting to search for the teaching file images. Without pre-existing knowledge of the folder name and contents, it is difficult to query the system for specific images. This is due to the fact that there is currently no fully satisfactory mechanism for categorizing, indexing, and searching cases using the PACS. There is currently no easy mechanism to save teaching, research, or clinical files onto a CD or other removable media or to automatically strip demographic or other patient information from the images. PACS vendors should provide much more sophisticated tools to create and annotate teaching file images in an easy to use but standard format (possibly Radiological Society of North America’s Medical Image Resource Center [MIRC] format) that could be exchanged with other sites and other vendors’ PAC systems. The privilege to create teaching or conference files should be given to the individual radiologists, technologists, and other users, and an audit should be kept of who has created these files, as well as keep track of who has accessed the files. Vendors should maintain a local PACS library of image quality phantoms, normal variants, and interesting cases and should have the capability of accessing central image repositories such as the RSNA’s MIRC images. Commercial PAC systems should utilize a standard lexicon to facilitate the creation and categorization of images, as well as to facilitate sharing of images and related text with other sites. This should be combined with a very easy to use mechanism to write images and related text when appropriate onto removable media (while maintaining a high level of security and confidentiality) to make it easier to share images for teaching, research, or clinical purposes.
Content-based image retrieval (CBIR) has been heralded as a mechanism to cope with the increasingly larger volumes of information present in medical imaging repositories. However, generic, extensible CBIR frameworks that work natively with Picture Archive and Communication Systems (PACS) are scarce. In this article we propose a methodology for parametric CBIR based on similarity profiles. The architecture and implementation of a profiled CBIR system, based on query by example, atop Dicoogle, an open-source, full-fletched PACS is also presented and discussed. In this solution, CBIR profiles allow the specification of both a distance function to be applied and the feature set that must be present for that function to operate. The presented framework provides the basis for a CBIR expansion mechanism and the solution developed integrates with DICOM based PACS networks where it provides CBIR functionality in a seamless manner.
This study presents a software technology to transform paper-based 12-lead electrocardiography (ECG) examination into (1) 12-lead ECG electronic diagnoses (e-diagnoses) and (2) mobile diagnoses (m-diagnoses) in emergency telemedicine. While Digital Imaging and Communications in Medicine (DICOM)-based images are commonly used in hospitals, the development of computerized 12-lead ECG is impeded by heterogeneous data formats of clinically used 12-lead ECG instrumentations, such as Standard Communications Protocol (SCP) ECG and Extensible Markup Language (XML) ECG. Additionally, there is no data link between clinically used 12-lead ECG instrumentations and mobile devices. To realize computerized 12-lead ECG examination procedures and ECG telemedicine, this study develops a DICOM-based 12-lead ECG information system capable of providing clinicians with medical images and waveform-based ECG diagnoses via Picture Archiving and Communication System (PACS). First, a waveform-based DICOM-ECG converter transforming clinically used SCP-ECG and XML-ECG to DICOM is applied to PACS for image- and waveform-based DICOM file manipulation. Second, a mobile Structured Query Language database communicating with PACS is installed in physicians’ mobile phones so that they can retrieve images and waveform-based ECG ubiquitously. Clinical evaluations of this system indicated the following. First, this developed PACS-dependent 12-lead ECG information system improves 12-lead ECG management and interoperability. Second, this system enables the remote physicians to perform ubiquitous 12-lead ECG and image diagnoses, which enhances the efficiency of emergency telemedicine. These findings prove the effectiveness and usefulness of the PACS-dependent 12-lead ECG information system, which can be easily adopted in telemedicine.
ECG; DICOM; PACS; telemedicine
The use of clinical imaging modalities within the pharmaceutical research space provides value and challenges. Typical clinical settings will utilize a Picture Archive and Communication System (PACS) to transmit and manage Digital Imaging and Communications in Medicine (DICOM) images generated by clinical imaging systems. However, a PACS is complex and provides many features that are not required within a research setting, making it difficult to generate a business case and determine the return on investment. We have developed a next-generation DICOM processing system using open-source software, commodity server hardware such as Apple Xserve®, high-performance network-attached storage (NAS), and in-house-developed preprocessing programs. DICOM-transmitted files are arranged in a flat file folder hierarchy easily accessible via our downstream analysis tools and a standard file browser. This next-generation system had a minimal construction cost due to the reuse of all the components from our first-generation system with the addition of a second server for a few thousand dollars. Performance metrics were gathered and the system was found to be highly scalable, performed significantly better than the first-generation system, is modular, has satisfactory image integrity, and is easier to maintain than the first-generation system. The resulting system is also portable across platforms and utilizes minimal hardware resources, allowing for easier upgrades and migration to smaller form factors at the hardware end-of-life. This system has been in production successfully for 8 months and services five clinical instruments and three pre-clinical instruments. This system has provided us with the necessary DICOM C-Store functionality, eliminating the need for a clinical PACS for day-to-day image processing.
PACS; DCMTK; DICOM; DICOM workflow; DICOM storage
The benefits of an integrated picture archiving and communication system/radiology information system (PACS/RIS) archive built with open source tools and methods are 2-fold. Open source permits an inexpensive development model where interfaces can be updated as needed, and the code is peer reviewed by many eyes (analogous to the scientific model). Integration of PACS/RIS functionality reduces the risk of inconsistent data by reducing interfaces among databases that contain largely redundant information. Also, wide adoption would promote standard data mining tools—reducing user needs to learn multiple methods to perform the same task. A model has been constructed capable of accepting HL7 orders, performing examination and resource scheduling, providing digital imaging and communications in medicine (DICOM) worklist information to modalities, archiving studies, and supporting DICOM query/retrieve from third party viewing software. The multitiered architecture uses a single database communicating via an ODBC bridge to a Linux server with HL7, DICOM, and HTTP connections. Human interaction is supported via a web browser, whereas automated informatics services communicate over the HL7 and DICOM links. The system is still under development, but the primary database schema is complete as well as key pieces of the web user interface. Additional work is needed on the DICOM/HL7 interface broker and completion of the base DICOM service classes.
Texas Children’s Hospital is a pediatric tertiary care facility in the Texas Medical Center with a large-scale, Digital Imaging and Communications in Medicine (DICOM)-compliant picture archival and communications system (PACS) installation. As our PACS has grown from an ultrasound niche PACS into a full-scale, multimodality operation, assuring continuity of clinical operations has become the number one task of the PACS staff. As new equipment is acquired and incorporated into the PACS, workflow processes, responsibilities, and job descriptions must be revised to accommodate filmless operations. Round-the-clock clinical operations must be supported with round-the-clock service, including three shifts, weekends, and holidays. To avoid unnecessary interruptions in clinical service, this requirement includes properly trained operators and users, as well as service personnel. Redundancy is a cornerstone in assuring continuity of clinical operations. This includes all PACS components such as acquisition, network interfaces, gateways, archive, and display. Where redundancy is not feasible, spare parts must be readily available. The need for redundancy also includes trained personnel. Procedures for contingency operations in the event of equipment failures must be devised, documented, and rehearsed. Contingency operations might be required in the event of scheduled as well as unscheduled service events, power outages, network outages, or interruption of the radiology information system (RIS) interface. Methods must be developed and implemented for reporting and documenting problems. We have a Trouble Call service that records a voice message and automatically pages the PACS Console Operator on duty. We also have developed a Maintenance Module on our RIS system where service calls are recorded by technologists and service actions are recorded and monitored by PACS support personnel. In a filmless environment, responsibility for the delivery of images to the radiologist and referring physician must be accepted by each imaging supervisor. Thus, each supervisor must initiate processes to verify correct patient and examination identification and the correct count and routing of images with each examination.
Sharing digital pathology images for enterprise- wide use into a picture archiving and communication system (PACS) is not yet widely adopted. We share our solution and 3-year experience of transmitting such images to an enterprise image server (EIS).
Gross pathology images acquired by prosectors were integrated with clinical cases into the laboratory information system's image management module, and stored in JPEG2000 format on a networked image server. Automated daily searches for cases with gross images were used to compile an ASCII text file that was forwarded to a separate institutional Enterprise Digital Imaging and Communications in Medicine (DICOM) Wrapper (EDW) server. Concurrently, an HL7-based image order for these cases was generated, containing the locations of images and patient data, and forwarded to the EDW, which combined data in these locations to generate images with patient data, as required by DICOM standards. The image and data were then “wrapped” according to DICOM standards, transferred to the PACS servers, and made accessible on an institution-wide basis.
In total, 26,966 gross images from 9,733 cases were transmitted over the 3-year period from the laboratory information system to the EIS. The average process time for cases with successful automatic uploads (n=9,688) to the EIS was 98 seconds. Only 45 cases (0.5%) failed requiring manual intervention. Uploaded images were immediately available to institution- wide PACS users. Since inception, user feedback has been positive.
Enterprise- wide PACS- based sharing of pathology images is feasible, provides useful services to clinical staff, and utilizes existing information system and telecommunications infrastructure. PACS-shared pathology images, however, require a “DICOM wrapper” for multisystem compatibility.
DICOM; digital image; LIS; PACS; pathology; wrapper
To evaluate portable media utilisation for image data sharing between enterprises. To predict the costs required to keep up with the trend. To identify related problems.
A software package was developed to include patient image data from CD into our normal workflow. The trend in the workload of CDs that were uploaded into a Picture Archiving and Communication System (PACS) over 89 months was analysed. The average number of images per month (and per investigation) was calculated to provide the estimation of storage and cost required in the whole process.
All Digital Imaging and Communications in Medicine (DICOM) files can be read from compact disc (CD) on any workstation in the hospital, processed quickly to the central server and checked after storage using the software tool. A total of 33,982,404 images from 88,952 CDs have been stored into the PACS system. In recent years, the stored images have reached an average of 4.2 terabytes (TB) uncompressed annually.
Integrated information about patients is clearly needed to provide easy and timely access to these data. The steadily growing storage can be solved by a more automated approach to portable media handling or the installation and acceptance of network-based transfer using cross-enterprise document sharing (XDS).
• Rapid assimilation of external imaging into a PACS system is essential.
• But data distribution using portable media also carries some disadvantages.
• A DICOM data uploader incorporates studies from portable media to hospital workflow.
• Automated media handling or XDS should solve the steadily growing storage problem.
• Software improvements will facilitate the steady increase in the amount of CDs processed.
Data sharing; Information distribution; CDROM; PACS (Radiology); Radiology information system
The presentation will focus on the implementation and utilization of a central picture archiving and communications system (PACS) network-monitoring tool that allows for enterprise-wide operations management and support of the image distribution network. The MagicWatch (Siemens, Iselin, NJ) PACS/radiology information system (RIS) monitoring station from Siemens has allowed our organization to create a service support structure that has given us proactive control of our environment and has allowed us to meet the service level performance expectations of the users. The Radiology Help Desk has used the MagicWatch PACS monitoring station as an applications support tool that has allowed the group to monitor network activity and individual systems performance at each node. Fast and timely recognition of the effects of single events within the PACS/RIS environment has allowed the group to proactively recognize possible performance issues and resolve problems. The PACS/operations group performs network management control, image storage management, and software distribution management from a single, central point in the enterprise. The MagicWatch station allows for the complete automation of software distribution, installation, and configuration process across all the nodes in the system. The tool has allowed for the standardization of the workstations and provides a central configuration control for the establishment and maintenance of the system standards. This report will describe the PACS management and operation prior to the implementation of the MagicWatch PACS monitoring station and will highlight the operational benefits of a centralized network and system-monitoring tool.
A distributed design is the most cost-effective system for small- to medium-scale picture archiving and communications systems (PACS) implementations. However, the design presents an interesting challenge to developers and implementers: to make stored image data, distributed throughout the PACS network, appear to be centralized with a single access point for users. A key component for the distributed system is a central or master database, containing all the studies that have been scanned into the PACS. Each study includes a list of one or more locations for that particular dataset so that applications can easily find it. Non-Digital Imaging and Communications in Medicine (DICOM) clients, such as our worldwide web (WWW)-based PACS browser, query the master database directly to find the images, then jump to the most appropriate location via a distributed web-based viewing system. The Master Database Broker provides DICOM clients with the same functionality by translating DICOM queries to master database searches and distributing retrieval requests transparently to the appropriate source. The Broker also acts as a storage service class provider, allowing users to store selected image subsets and reformatted images with the original study, without having to know on which server the original data are stored.
Common object request broker architecture (CORBA) is a method for invoking distributed objects across a network. There has been some activity in applying this software technology to Digital Imaging and Communications in Medicine (DICOM), but no documented demonstration of how this would actually work. We report a CORBA demonstration that is functionally equivalent and in some ways superior to the DICOM communication protocol. In addition, in and outside of medicine, there is great interest in the use of extensible markup language (XML) to provide interoperation between databases. An example implementation of the DICOM data structure in XML will also be demonstrated. Using Visibroker ORB from Inprise (Scotts Valley, CA), a test bed was developed to simulate the principle DICOM operations: store, query, and retrieve (SQR). SQR is the most common interaction between a modality device application entity (AE) such as a computed tomography (CT) scanner, and a storage component, as well as between a storage component and a workstation. The storage of a CT study by invoking one of several storage objects residing on a network was simulated and demonstrated. In addition, XML database descriptors were used to facilitate the transfer of DICOM header information between independent databases. CORBA is demonstrated to have great potential for the next version of DICOM. It can provide redundant protection against single points of failure. XML appears to be an excellent method of providing interaction between separate databases managing the DICOM information object model, and may therefore eliminate the common use of proprietary client-server databases in commercial implementations of picture archiving and communication systems (PACS).
To meet the educational needs of a medical imaging department with a strong teaching commitment, a teaching file that uses digital data supplied by the institutional picture archiving and communications system (PACS) was required. This teaching file had to be easily used by the end users, have a simple submission process, be able to support multiple users, be searchable on all data fields, and implementing the teaching file must not incur any additional software or hardware costs. The teaching file developed to address this problem takes advantage of the database structure and capabilities of several components included in the commercial PACS installed at the hospital. MS Access is used to seamlessly integrate with the digital imaging and communication in medicine (DICOM) database of a normal work station that is part of the PACS. This integration allows relevant patient and study demographics to be copied from images of interest and then to be stored in a separate database as the back-end of the digital teaching file. When images for a particular teaching file case need to be reviewed, they are automatically retrieved and displayed from the main PACS database using an open application programming interface (API) connection defined on the PACS web server. Utilizing this open API connection means the teaching file contains only the relevant demographic information of each teaching file case; no image data is stored locally. The open API connection allows access to imaging data usually not encountered in a teaching file, allowing more comprehensive imaging case files to be developed by the radiologist. Other advantages of this teaching file design are that it does not duplicate image data, it is small allowing simple ongoing backup, and it can be opened with multiple users accessing the database without compromising data access or integrity.
Electronic teaching files; DICOM; PACS
The University of California at San Francisco (USCF) Department of Radiology currently has a clinically operational picture archiving and communication system (PACS) that is thirty-five percent filmless, with the goal of becoming seventy-five percent filmless within the year. The design and implementation of the clinical PACS has been a collaborative effort between an academic research laboratory and a commercial vendor partner. Images are digitally acquired from three computed radiography (CR) scanners, five computed tomography (CT) scanners, five magnetic resonance (MR) imagers, three digital fluoroscopic rooms, an ultrasound mini-PACS and a nuclear medicine mini-PACS. The DICOM (Digital Imaging and Communications in Medicine) standard communications protocol and image format is adhered to throughout the PACS. Images are archived in hierarchical staged fashion, on a RAID (redundant array of inexpensive disks) and on magneto-optical disk jukeboxes. The clinical PACS uses an object-oriented Oracle SQL (systems query language) database, and interfaces to the Radiology Information System using the HL7 (Health Languages 7) standard. Components are networked using a combination of switched and fast ethernet, and ATM (asynchronous transfer mode), all over fiber optics. The wide area network links six UCSF sites in San Francisco. A combination of high and medium resolution dual-monitor display stations have been placed throughout the Department of Radiology, the Emergency Department (ED) and Intensive Care Units (ICU). A continuing quality improvement (CQI) committee has been formed to facilitate the PACS installation and training, workflow modifications, quality assurance and clinical acceptance. This committee includes radiologists at all levels (resident, fellow, attending), radiology technologists, film library personnel, ED and ICU clinian end-users, and PACS team members. The CQI committee has proved vital in the creation of new management procedures, providing a means for user feedback and education, and contributing to the overall acceptance of, and user satisfaction with the system. Well developed CQI procedures have been essential to the successful clinical operation of the PACS as UCSF Radiology moves toward, a filmless department.
PACS; continuing quality improvement (CQI); quality assurance (QA); filmless
Purpose: To identify practical issues surrounding delivering digital images from picture archiving and communication systems (PACS) for research and teaching purposes. The complexity of Digital Imaging and Communications in Medicine (DICOM) access methods, security, patient confidentiality, PACS database integrity, portability, and scalability are discussed. A software prototype designed to resolve these issues is described.System Architecture: A six-component, three-tier, client server software application program supporting DICOM query/retrieve services was developed in the JAWA language. This software was interfaced to a large GE (Mt Prospect, IL) Medical Systems clinical PACS at Northwestern Memorial Hospital (NMH).Conclusion: Images can be delivered from a clinical PACS for research and teaching purposes. Concerns for security, patient confidentiality, integrity of the PACS database, and management of the transactions can be addressed. The described software is one such solution for achieving this goal.
The US Department of Veterans Affairs is integrating imaging functionality into the healthcare enterprise using the Digital Imaging and Communication in Medicine (DICOM) standard protocols. The VA’s VistA Hospital Information System (HIS) is installed at all 170 VA medical centers across the country. Image management is supported by the VistA HIS in several ways. Some VA sites have commercial Picture Archiving and Communication Systems (PACS) interfaced to the VistA HIS, while other sites use the direct image acquisition and diagnostic display capabilities of VistA itself. By supporting a small set of DICOM services, VistA can transmit patient and study text data to the image producing modalities and the commercial PACS, and enable images and study data to be transferred back. Images can be displayed on low-cost clinician’s workstations or high-resolution diagnostic quality multi-monitor workstations located within a facility or elsewhere on the healthcare enterprise wide area network.
Interfaces; HIS; RIS; PACS; DICOM; Enterprise Imaging Systems
Purpose: Distributed archives in a picture archiving and communication system (PACS) environment can provide added fault tolerance and fail-over capability, as well as increased load capacity at a more economical price than traditional “high-availability” systems. Systems can be configured with varying levels of fault tolerance, depending on the amountof redundancy desired. There is, however, a direct correlation between the level of hardware redundancy and cost to implement. This presentation details the system design for fault-tolerant distributed archives as well as several options for redundancy, referencing implementation of a fault-tolerant archivesystem at the University of Utah.Methods: The distributed archive system described here is based on Image Devices’ image archive software, which can be implemented on multiple individual archive servers in order to distribute archive functionality and operational load. The configuration and implementation of the individual servers together make up the distributed archive system and does not impact the ability of the system to be scaled to meet future requirements. Several implementation and configuration options exist, including the ability for servers to maintain replicated databases containing pateintand image information. Thus, each archive can be aware of all information and the location of this information within the distributed archive system.Results: The goal is to produce systems that will still be operational in the event of any single point of failure, ie, a network connection failure between facilities or the failure of asingle archive server within the distributed system. During normal operation, workload forimage acquisition, image routing and image query requests will be distributed between the archive servers. If the system is deployed in a multifacility environment, each archive server can be configured to be responsible for the acquisition and image distribution management within that server’s localfacility. If the system is deployed in a single facility environment, load can be distributed evenly between the archive servers based on an understanding of the workload requirements generated be each acquisition and display device in the system. In the event that an archive server fails, other archive servers within the system will have the ability to provide redundancy employed. Three levels of fault-tolerant design can be achieved with this system architecture: (1) duplicate work capability only; (2) duplicate work capability and short-term image cache; (3) duplicate work capability,short-term image cache, and long-term image archival. Using the basic fault-tolerant design above, we have implemented a multifacility distributedarchive system at the University of Utah. This system was implemented at a fraction of the cost of true “high-availability” archive architectures yet provides constant up time for the PACS system. If the network connection between thetwo locations goes down, each siteis still fully functional for soft-copy read, as well as image acquisition and distribution. If either of the archiveservers goes down, the image sources are redirected to the other archive server. The operational server then handles image distribution for both locations. Access to images in the short-term image cache is available to both archive servers and is not affected by loss of the network connection or remoteserver. Because there is ony one long-term archivedevice, the ability to retrieve images from long-term storage is theonly function compromised by a network or server failure.Conclusion: By implementing distributed archives in a PACS environment, it is possible to achieve a highly fault-tolerant system without the expense of high-availability hardware and software. The design concepts outlined here can be applied to any PACS system that supports distributed archive functionality.
With the growing computing capability of mobile phones, a handy mobile controller is developed for accessing the picture archiving and communication system (PACS) to enhance image management for clinicians with nearly no restriction in time and location using various wireless communication modes. The PACS is an integrated system for the distribution and archival of medical images that are acquired by different imaging modalities such as CT (computed tomography) scanners, CR (computed radiography) units, DR (digital radiography) units, US (ultrasonography) scanners, and MR (magnetic resonance) scanners. The mobile controller allows image management of the PACS including display, worklisting, query and retrieval of medical images in DICOM format. In this mobile system, a server program is developed in a PACS Web server which serves as an interface for client programs in the mobile phone and the enterprise PACS for image distribution in hospitals. The application processing is performed on the server side to reduce computational loading in the mobile device. The communication method of mobile phones can be adapted to multiple wireless environments in Hong Kong. This allows greater feasibility to accommodate the rapidly changing communication technology. No complicated computer hardware or software is necessary. Using a mobile phone embedded with the mobile controller client program, this system would serve as a tool for heath care and medical professionals to improve the efficiency of the health care services by speedy delivery of image information. This is particularly important in case of urgent consultation, and it allows health care workers better use of the time for patient care.
Mobile phone; PACS; PDA; filmless; medical images; health care
To address issues in interoperability between different fundus image systems, we proposed a web eye-picture archiving and communication system (PACS) framework in conformance with digital imaging and communication in medicine (DICOM) and health level 7 (HL7) protocol to realize fundus images and reports sharing and communication through internet.
Firstly, a telemedicine-based eye care work flow was established based on integrating the healthcare enterprise (IHE) Eye Care technical framework. Then, a browser/server architecture eye-PACS system was established in conformance with the web access to DICOM persistent object (WADO) protocol, which contains three tiers.
In any client system installed with web browser, clinicians could log in the eye-PACS to observe fundus images and reports. Multipurpose internet mail extensions (MIME) type of a structured report is saved as pdf/html with reference link to relevant fundus image using the WADO syntax could provide enough information for clinicians. Some functions provided by open-source Oviyam could be used to query, zoom, move, measure, view DICOM fundus images.
Such web eye-PACS in compliance to WADO protocol could be used to store and communicate fundus images and reports, therefore is of great significance for teleophthalmology.
picture archiving and communication system; teleophthalmology; integrating the healthcare enterprise; web access to DICOM persistent object
A picture archive and communications system (PACS) is a rich source of images and data suitable for creating electronic teaching files (ETF). However, the potential for PACS to support nonclinical applications has not been fully realized: at present there is no mechanism for PACS to identify and store teaching files; neither is there a standardized method for sharing such teaching images. The Medical Image Resource Center (MIRC) is a new central image repository that defines standards for data exchange among different centers. We developed an ETF server that retrieves digital imaging and communication in medicine (DICOM) images from PACS, and enables users to create teaching files that conform to the new MIRC schema. We test-populated our ETF server with illustrative images from the clinical case load of the National Neuroscience Institute, Singapore. Together, PACS and MIRC have the potential to benefit radiology teaching and research.
electronic teaching files; PACS; computer server; Radiological Society of North America; Medical Image Resource Center; medical education
Verifying the integrity of DICOM files transmitted between separate archives (eg, storage service providers, network attached storage, or storage area networks) is of critical importance. The software application described in this article retrieves a specified number of DICOM studies from two different DICOM storage applications; the primary picture archiving and communication system (PACS) and an off-site long-term archive. The system includes a query/retrieve (Q/R) module, storage service class provider (SCP), a DICOM comparison module, and a graphical user interface. The system checks the two studies for DICOM 3.0 compliance and then verifies that the DICOM data elements and pixel data are identical. Discrepancies in the two data sets are recorded with the data elements (tag number, value representation, value length, and value field) and pixel data (pixel value and pixel location) in question. The system can be operated automatically, in batch mode, and manually to meet a wide variety of use cases. We ran this program on a 15% statistical sample of 50,000 studies (7500 studies examined). We found 2 pixel data mismatches (resolved on retransmission) and 831 header element mismatches. We subsequently ran the program against a smaller batch of 1000 studies, identifying no pixel data mismatches and 958 header element mismatches. Although we did not find significant issues in our limited study, given other incidents that we have experienced when moving images between systems, we conclude that it is vital to maintain an ongoing, automatic, systematic validation of DICOM transfers so as to be proactive in preventing possibly catastrophic data loss.
DICOM; file verification and comparison; PACS
Information technology (IT), long taken for granted in commercial settings, is now being utilized for healthcare applications. Medical imaging has lagged comparatively due to the extremely vast data content of each frame; thus, the requirement for expensive high-end components. Further, IT in radiology has evolved from two distinctly separate camps—information systems, known as RIS (radiology information systems) and PACS (picture archiving and communications systems). Both RIS and PACS applications have migrated to the PC environment, enabling cost-effective implementation, but from two backgrounds: RIS from vendors using conventional information systems platforms and products, and PACS from radiographic film and modality vendors. The radiology department at Texas Tech University has assembled a seamlessly integrated, enterprise-wide RIS/PACS/teleradiology intranet. The design criteria include user-friendliness, flexibility to respond to changing needs, and open modular architecture to assure interoperability, cost-effectiveness, and future-proofing of investment. Since no single venor could provide an integrated system meeting our specifications, we decided to assume the burden of constructing our own system. As the system integrator, we embrace open architecture, thus enabling the incorporation of industry-standard-compliant, COTS (commercially off the shelf) products as modules. Microsoft Windows NT operating system, Visual C++ programming language, TCP/IP (transmission control protocol/internetworking protocol), relational SQL (structured query language) database, ODBC (open database connectivity), HL-7 (health level seven) and DICOM (digital imaging and communications in medicine) interfaces are utilized. The usage of COTS components reduces the cost to very affordable levels. With this approach, any module in our system can be replaced when outmoded, without affecting other modules in our system, making it truly future-proof. Construction and evolution of our system (TECHRAD) is reviewed.
The United States Department of Veterans Affairs is integrating imaging into the healthcare enterprise by using the Digital Imaging and Communication in Medicine (DICOM) standard protocols. Image management is directly integrated into the VistA Hospital Information System (HIS) software and clinical database. Radiology images are acquired with DICOM and are stored directly in the HIS database. Images can be displayed on low-cost clinician’s workstations throughout the medical center. High-resolution diagnostic quality multimonitor VistA workstations with specialized viewing software can be used for reading radiology images. Two approaches are used to acquire and handle images within the radiology department. Some sites have a commercial Picture Archiving and Communications System (PACS) interfaced to the VistA HIS, whereas other sites use the direct image acquisition and integrated diagnostic display capabilities of VistA itself. A small set of DICOM services has been implemented by VistA to allow patient and study text data to be transmitted to image producing modalities and the commercial PACS, and to enable images and study data to be transferred back. DICOM has been the cornerstone in the ability to integrate imaging functionality into the healthcare enterprise. Because of its openness, it allows the integration of system components from commercial and noncommercial sources to work together to provide functional cost-effective solutions.
HIS/RIS; DICOM; PACS
The most frequently asked question without a correct answer is: “Just how many people does it take to operate a picture archiving and communication system (PACS)?” At Texas Children’s Hospital, our consensus is that we do not yet know. As soon as we felt we had adequate staffing to provide timely response for routine services, we found that including the Intensive Care Units (ICUs) increased our demand for urgent response beyond our capacity. The addition of inpatient bedside imaging to PACS also increased the demand for round-the-clock and weekend PACS services. Our answer to the staffing question changes every year, in accordance with changes in the scope of services that our PACS is expected to provide. Our administration drew up a 5-year plan for PACS implementation, concentrating on purchase and installation of equipment, but neglected to estimate requirements for full-time equivalents (FTEs) for PACS. Our administration reasonably assumed that existing employees would be galvanized into PACS personnel. It is now clear that new FTEs need to be created strictly for the PACS service. Our 5-year plan also did not anticipate significant changes in the extent of our healthcare enterprise. Our PACS accommodates limited remote service: providing a PACS Analyst to travel to the site when a problem is not resolved remotely is another demand on staffing. Our PACS service was formed using staffing numbers based on assumptions about the minimum number of employees needed to perform routine duties, field trouble calls, conduct training, and work on special projects, such as adding new acquisition modalities or troubleshooting longstanding problems. This staffing was based on a single shift operation, with on-call coverage for second, third, and weekend shifts. The number of employees also considered absences for vacation, sick leave, and training. The service has administrative overhead that should be covered by a secretary. Someone is also needed to supervise the team. Once the number of personnel is determined, detailed definition of qualifications and responsibilities is required. Each job description must accurately reflect what is expected of the employee, but must be constructed in such a way to be graded appropriately by Human Resources, without excluding potentially desirable applicants. In addition to competitive pay. other factors play an important role in recruiting and retention. These include training that the hospital provides, opportunities for advancement, relief from menial duties, adequate working space and facilities, and opportunities for self-development. There is high turnover of personnel in computer services, and we are in a highly competitive market. The correct number of FTEs must consider that we will have to operate the PACS during periods when one or more positions are open or occupied by “greenhorns.” In our case, where the vendor provides on-site service engineers, we are able to operate with fewer FTEs. The more distant and tenuous our vendor support, the more we would need to depend on hospital FTEs. While remote vendor maintenance is helpful, it is not useful in reducing the number of FTEs. Instead of adding PACS responsibilities to supervisors of imaging services, we are creating new PACS FTEs outside the PACS service. The idea is to give imaging supervisors the assets they need to perform the additional tasks involving PACS, such as first-line response to trouble, user training, and quality-control oversight. It also frees up PACS service personnel to deal with training and problems with customers outside the Radiology Department.
Electronic archiving of radiology images over many years will require many terabytes of storage with a need for rapid retrieval of these images. As more large PACS installations are installed and implemented, a data crisis occurs. The ability to store this large amount of data using the traditional method of optical jukeboxes or online disk alone becomes an unworkable solution. The amount of floor space, number of optical jukeboxes, and off-line shelf storage required to store the images becomes unmanageable. With the recent advances in tape and tape drives, the use of tape for long term storage of PACS data has become the preferred alternative. A PACS system consisting of a centrally managed system of RAID disk, software and at the heart of the system, tape, presents a solution that for the first time solves the problems of multi-modality high end PACS, non-DICOM image, electronic medical record and ADT data storage. This paper will examine the installation of the University of Utah, Department of Radiology PACS system and the integration of automated tape archive. The tape archive is also capable of storing data other than traditional PACS data. The implementation of an automated data archive to serve the many other needs of a large hospital will also be discussed. This will include the integration of a filmless cardiology department and the backup/archival needs of a traditional MIS department. The need for high bandwidth to tape with a large RAID cache will be examined and how with an interface to a RIS pre-fetch engine, tape can be a superior solution to optical platters or other archival solutions. The data management software will be discussed in detail. The performance and cost of RAID disk cache and automated tape compared to a solution that includes optical will be examined.