DICOM Modality Worklist: An essential component in a PACS environment

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

An Integrated Approach to a Teaching File Linked to 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.     

A literature review on communication between picture archiving and communication systems and radiology information systems and/or hospital information systems

The purpose of this literature review is to present the concepts surrounding the issue of communication between imaging systems and information systems in radiology and the literature about them. Picture archiving and communication systems (PACS) were developed to combine viewing of modality images, archiving, and distribution of images. When PACS is integrated/interfaced with radiology information systems (RIS) or hospital information systems (HIS), it can merge patient demographics, medical records, and images. To address several issues surrounding communication between PACS and HIS/RIS and to make interface development easier and faster, various organizations have developed standards for the formatting and transfer of clinical data. Additional work continues to better handle these issues. Communication protocol Health Level 7 (HL7) is a standard application protocol used for electronic text data exchange in health care by most HIS/RIS. The imaging communication protocol for PACS is the Digital Imaging and Communications in Medicine (DICOM) standard specification protocol that describes the means of formatting and exchanging images and associated information.     

An efficient architecture to support digital pathology in standard medical imaging repositories

In the past decade, digital pathology and whole-slide imaging (WSI) have been gaining momentum with the proliferation of digital scanners from different manufacturers. The literature reports significant advantages associated with the adoption of digital images in pathology, namely, improvements in diagnostic accuracy and better support for telepathology. Moreover, it also offers new clinical and research applications. However, numerous barriers have been slowing the adoption of WSI, among which the most important are performance issues associated with storage and distribution of huge volumes of data, and lack of interoperability with other hospital information systems, most notably Picture Archive and Communications Systems (PACS) based on the DICOM standard.This article proposes an architecture of a Web Pathology PACS fully compliant with DICOM standard communications and data formats. The solution includes a PACS Archive responsible for storing whole-slide imaging data in DICOM WSI format and offers a communication interface based on the most recent DICOM Web services. The second component is a zero-footprint viewer that runs in any web-browser. It consumes data using the PACS archive standard web services. Moreover, it features a tiling engine especially suited to deal with the WSI image pyramids. These components were designed with special focus on efficiency and usability. The performance of our system was assessed through a comparative analysis of the state-of-the-art solutions. The results demonstrate that it is possible to have a very competitive solution based on standard workflows.     

Evaluating the digital storage requirements for a partial picture archive and communication system

The study evaluates the volume of digital images produced in a department of diagnostic imaging, with the primary goal of identifying the requirements of digital storage for a partial picture archive and communication system (PACS). The daily activity of digital units (one computed tomography unit, one magnetic resonance imaging, two ultrasonography, and one digital subtraction angiography), which perform 25% of total examinations in the department, was analyzed to determine the number of images produced by digital techniques. They account for 65% to 70% of the total images. The storage capacity necessary to contain all digital data produced in a 800-bed hospital reaches nearly 100 Gbyte/yr without compression. The study emphasizes that a partial PACS can be economically justified through reduced film-archiving costs. This goal could be achieved through a selection of significant images and examinations, considerably reducing the cost of film reproduction and allowing the amortization of a partial PACS in about 5 or 6 years.     

Computers in imaging and health care: Now and in the future

Early picture archiving and communication systems (PACS) were characterized by the use of very expensive hardware devices, cumbersome display stations, duplication of database content, lack of interfaces to other clinical information systems, and immaturity in their understanding of the folder manager concepts and workflow reengineering. They were implemented historically at large academic medical centers by biomedical engineers and imaging informaticists. PACS were nonstandard, home-grown projects with mixed clinical acceptance. However, they clearly showed the great potential for PACS and filmless medical imaging. Filmless radiology is a reality today. The advent of efficient softcopy display of images provides a means for dealing with the ever-increasing number of studies and number of images per study. Computer power has increased, and archival storage cost has decreased to the extent that the economics of PACS is justifiable with respect to film. Network bandwidths have increased to allow large studies of many megabytes to arrive at display stations within seconds of examination completion. PACS vendors have recognized the need for efficient workflow and have built systems with intelligence in the management of patient data. Close integration with the hospital information system (HIS)-radiology information system (RIS) is critical for system functionality. Successful implementation of PACS requires integration or interoperation with hospital and radiology information systems. Besides the economic advantages, secure rapid access to all clinical information on patients, including imaging studies, anytime and anywhere, enhances the quality of patient care, although it is difficult to quantify. Medical image management systems are maturing, providing access outside of the radiology department to images and clinical information throughout the hospital or the enterprise via the Internet. Small and medium-sized community hospitals, private practices, and outpatient centers in rural areas will begin realizing the benefits of PACS already realized by the large tertiary care academic medical centers and research institutions. Hand-held devices and the Worldwide Web are going to change the way people communicate and do business. The impact on health care will be huge, including radiology. Computer-aided diagnosis, decision support tools, virtual imaging, and guidance systems will transform our practice as value-added applications utilizing the technologies pushed by PACS development efforts. Outcomes data and the electronic medical record (EMR) will drive our interactions with referring physicians and we expect the radiologist to become the informaticist, a new version of the medical management consultant.     

The Information Security Needs in Radiological Information Systems—an Insight on State Hospitals of Iran, 2012

Picture Archiving and Communications System (PACS) was originally developed for radiology services over 20 years ago to capture medical images electronically. Medical diagnosis methods are based on images such as clinical radiographs, ultrasounds, CT scans, MRIs, or other imaging modalities. Information obtained from these images is correlated with patient information. So with regards to the important role of PACS in hospitals, we aimed to evaluate the PACS and survey the information security needed in the Radiological Information system. First, we surveyed the different aspects of PACS that should be in any health organizations based on Department of Health standards and prepared checklists for assessing the PACS in different hospitals. Second, we surveyed the security controls that should be implemented in PACS. Checklists reliability is affirmed by professors of Tehran Science University. Then, the final data are inputted in SPSS software and analyzed. The results indicate that PACS in hospitals can transfer patient demographic information but they do not show route of information. These systems are not open source. They don’t use XML-based standard and HL7 standard for exchanging the data. They do not use DS digital signature. They use passwords and the user can correct or change the medical information. PACS can detect alternation rendered. The survey of results demonstrates that PACS in all hospitals has the same features. These systems have the patient demographic data but they do not have suitable flexibility to interface network or taking reports. For the privacy of PACS in all hospitals, there were passwords for users and the system could show the changes that have been made; but there was no water making or digital signature for the users.     

The impact of a picture archiving and communication system on nuclear medicine examination interpretation

Radiographic correlation is essential for many of the examinations performed in nuclear medicine. The purpose of this study was to evaluate the impact of a picture archiving and communications system (PACS) on the function and efficiency of a nuclear medicine department at a tertiary care institution. We evaluated 250 consecutive noncardiac nuclear medicine imaging examinations and asked the interpreting physician the following questions: (1) Was PACS used in the interpretation of the study? (2) Did the use of PACS expedite examination completion or aid in study interpretation? And (3) Did the use of PACS permit a definitive diagnosis to be made? PACS was accessed for correlative radiographic images in 155 of the 250 (62%) nuclear medicine examinations. Images available on PACS for review aided in study interpretation in 74% (115 of 155) of cases The use of PACS was thought to expedite examination completion in 55% (86 of 155) of cases. The system was accessed but not operational in only 1% of cases (2 of 155). PACS provides reliable, rapid access to multimodality correlative radiographic images that aid in the interpretation of nuclear medicine examinations. Such systems also increase the efficiency of a nuclear medicine service by allowing timely and conclusive interpretations to be made.Key words: picture archive and communication systems, computers, nuclear medicine     

Medical Image Resource Center–making electronic teaching files from PACS

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.     

Enterprise-wide Implementation of Digital Radiography in Oral and Maxillofacial Imaging: The University of Florida Dentistry System

The implementation of digital radiography in dentistry in a large healthcare enterprise setting is discussed. A distinct need for a dedicated dental picture archiving and communication systems (PACS) exists for seamless integration of different vendor products across the system. Complex issues are contended with as each clinical department migrated to a digital environment with unique needs and workflow patterns. The University of Florida has had a dental PACS installed over 2 years ago. This paper describes the process of conversion from film-based imaging from the planning stages through clinical implementation. Dentistry poses many unique challenges as it strives to achieve better integration with systems primarily designed for imaging; however, the technical requirements for high-resolution image capture in dentistry far exceed those in medicine, as most routine dental diagnostic tasks are challenging. The significance of specification, evaluation, vendor selection, installation, trial runs, training, and phased clinical implementation is emphasized.     

一种符合医学数字影像与通讯标准的医学影像管理系统的设计

医学影像的存储与传输在数字化医疗快速发展的今天占据着非常重要的地位。为了实现医学数字影像与通讯（DICOM）医学影像在局域网上的传输和查询,本文设计了一个符合DICOM标准的医学影像管理系统。该系统能对DICOM格式文件进行解析,并在数据库中把DICOM影像文件与对应的病历信息进行关联存储,可以给医院影像科提供完全数字化的影像和数据。此研究工作不仅满足了医院影像中心对大量影像数据存储的需求,同时也促进了PACS系统的发展。     

System Integration and DICOM Image Creation for PET-MR Fusion

This article demonstrates a gateway system for converting image fusion results to digital imaging and communication in medicine (DICOM) objects. For the purpose of standardization and integration, we have followed the guidelines of the Integrated Healthcare Enterprise technical framework and developed a DICOM gateway. The gateway system combines data from hospital information system, image fusion results, and the information generated itself to constitute new DICOM objects. All the mandatory tags defined in standard DICOM object were generated in the gateway system. The gateway system will generate two series of SOP instances of each PET-MR fusion result; SOP (Service Object Pair) one for the reconstructed magnetic resonance (MR) images and the other for position emission tomography (PET) images. The size, resolution, spatial coordinates, and number of frames are the same in both series of SOP instances. Every new generated MR image exactly fits with one of the reconstructed PET images. Those DICOM images are stored to the picture archiving and communication system (PACS) server by means of standard DICOM protocols. When those images are retrieved and viewed by standard DICOM viewing systems, both images can be viewed at the same anatomy location. This system is useful for precise diagnosis and therapy.     

Design and Implementation of Disaster Recovery and Business Continuity Solution for Radiology PACS

In the digital era of radiology, picture archiving and communication system (PACS) has a pivotal role in retrieving and storing the images. Integration of PACS with all the health care information systems e.g., health information system, radiology information system, and electronic medical record has greatly improved access to patient data at anytime and anywhere throughout the entire enterprise. In such an integrated setting, seamless operation depends critically on maintaining data integrity and continuous access for all. Any failure in hardware or software could interrupt the workflow or data and consequently, would risk serious impact to patient care. Thus, any large-scale PACS now have an indispensable requirement to include deployment of a disaster recovery plan to ensure secure sources of data. This paper presents our experience with designing and implementing a disaster recovery and business continuity plan. The selected architecture with two servers in each site (local and disaster recovery (DR) site) provides four different scenarios to continue running and maintain end user service. The implemented DR at University Hospitals Health System now permits continuous access to the PACS application and its contained images for radiologists, other clinicians, and patients alike.     

A digital imaging and communications in medicine (DICOM) print service for chest imaging

Large-scale picture archiving and communication systems (PACS) have not been widely implemented in this or other countries. In almost all radiology departments film remains the medium for diagnostic interpretation and image archive. Chest imaging is the dominant screening examination performed within most imaging departments and as such, is an extremely high-volume, low-margin examination. Digital technologies are being applied to chest imaging to overcome limitations of screen-film receptors (limited latitude) and current film management systems (singleimage copy). Efficient management of images and information is essential to the success of a chest imaging program. In this article we report on a digital imaging and communications in medicine (DICOM)-based centralized printing network for chest imaging. The system components and their operational characteristics are described. Our experience integrating DICOM-compliant equipment supplied by several vendors is described. We conclude that the print model supported by DICOM is adequate for cross-sectional (eg, computed tomography and magnetic resonance) imaging but is too simplistic to be generally applied to projection radiography.     

A concept-based retrieval system for thoracic radiology

Current digital information systems in radiology are insufficient to accommodate the retrieval needs of academicians. Significant efforts are required in retrieving clinical cases for teaching and research. We describe a prototype system that supports intelligent case retrieval based on a combined specification of patient demographics, radiologic findings, and pathologic diagnoses. The documents for these cases can be distributed among multiple heterogeneous data bases. The system features automatic indexing of radiology and pathology reports, a comprehensive lexicon for thoracic radiology, an interface to a hospital information system, radiology information system, and picture archiving and communication systems, and a graphical user interface for query formulation and results visualization. The prototype system was developed within the domain of thoracic radiology involving patients with lung cancer.     

Integration of Temporal Subtraction and Nodule Detection System for Digital Chest Radiographs into Picture Archiving and Communication System (PACS): Four-year Experience

Since May 2002, temporal subtraction and nodule detection systems for digital chest radiographs have been integrated into our hospital’s picture archiving and communication systems (PACS). Image data of digital chest radiographs were stored in PACS with the digital image and communication in medicine (DICOM) protocol. Temporal subtraction and nodule detection images were produced automatically in an exclusive server and delivered with current and previous images to the work stations. The problems that we faced and the solutions that we arrived at were analyzed. We encountered four major problems. The first problem, as a result of the storage of the original images’ data with the upside-down, reverse, or lying-down positioning on portable chest radiographs, was solved by postponing the original data storage for 30 min. The second problem, the variable matrix sizes of chest radiographs obtained with flat-panel detectors (FPDs), was solved by improving the computer algorithm to produce consistent temporal subtraction images. The third problem, the production of temporal subtraction images of low quality, could not be solved fundamentally when the original images were obtained with different modalities. The fourth problem, an excessive false-positive rate on the nodule detection system, was solved by adjusting this system to chest radiographs obtained in our hospital. Integration of the temporal subtraction and nodule detection system into our hospital’s PACS was customized successfully; this experience may be helpful to other hospitals.     

Architectural design and tools to support the transparent access to hospital information systems,radiology information systems,and picture archiving and communication systems

The fragmentation of the electronic patient record among hospital information systems (HIS), radiology information systems (RIS), and picture archiving and communication systems (PACS) makes the viewing of the complete medical patient record inconvenient. The purpose of this report is to describe the system architecture, development tools, and implementation issues related to providing transparent access to HIS, RIS, and PACS information. A client-mediator-server architecture was implemented to facilitate the gathering and visualization of electronic medical records from these independent heterogeneous information systems. The architecture features intelligent data access agents, run-time determination of data access strategies, and an active patient cache. The development and management of the agents were facilitated by data integration CASE (computer-assisted software engineering) tools. HIS, RIS, and PACS data access and translation agents were successfully developed. All pathology, radiology, medical, laboratory, admissions, and radiology reports for a patient are available for review from a single integrated workstation interface. A data caching system provides fast access to active patient data. New network architectures are evolving that support the integration of heterogeneous software subsystems. Commercial tools are available to assist in the integration procedure.     

An integrated picture archiving and communications system-radiology information system in a radiological department

In this report we present an integrated picture archiving and communication system (PACS)-radiology information system (RIS) which runs as part of the daily routine in the Department of Radiology at the University of Graz. Although the PACS and the RIS have been developed independently, the two systems are interfaced to ensure a unified and consistent long-term archive. The configuration connects four computer tomography scanners (one of them situated at a distance of 1 km), a magnetic resonance imaging scanner, a digital subtraction angiography unit, an evaluation console, a diagnostic console, an image display console, an archive with two optical disk drives, and several RIS terminals. The configuration allows the routine archiving of all examinations on optical disks independent of reporting. The management of the optical disks is performed by the RIS. Images can be selected for retrieval via the RIS by using patient identification or medical criteria. A special software process (PACS-MONITOR) enables the user to survey and manage image communication, archiving, and retrieval as well as to get information about the status of the system at any time and handle the different procedures in the PACS. The system is active 24 hours a day. To make the PACS operation as independent as possible from the permanent presence of a system manager (electronic data processing expert), a rule-based expert system (OPERAS; OPERating ASsistant) is in use to localize and eliminate malfunctions that occur during routine work. The PACS-RIS reduces labor and speeds access to images within radiology and clinical departments.