Why and how is soft copy reading possible in clinical practice?
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The properties of the human visual system (HVS) relevant to the diagnostic process are described after a brief introduction on the general problems and advantages of using soft copy for primary radiology interpretations. At various spatial and temporal frequencies the contrast sensitivity defines the spatial resolution of the eye-brain system and the sensitivity to flicker. The adaptation to the displayed radiological scene and the ambient illumination determine the dynamic range for the operation of the HVS. Although image display devices are determined mainly by state-of-the-art technology, analysis of the HVS may suggest technical characteristics for electronic displays that will help to optimize the display to the operation of the HVS. These include display size, spatial resolution, contrast resolution, luminance range, and noise, from which further consequences for the technical components of a monitor follow. It is emphasized that routine monitor quality control must be available in clinical practice. These image quality measures must be simple enough to be applied as part of the daily routine. These test instructions might also serve as elements of technical acceptance and constancy tests. (+info)
Computerized analysis of abnormal asymmetry in digital chest radiographs: evaluation of potential utility.
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The purpose of this study was to develop and test a computerized method for the fully automated analysis of abnormal asymmetry in digital posteroanterior (PA) chest radiographs. An automated lung segmentation method was used to identify the aerated lung regions in 600 chest radiographs. Minimal a priori lung morphology information was required for this gray-level thresholding-based segmentation. Consequently, segmentation was applicable to grossly abnormal cases. The relative areas of segmented right and left lung regions in each image were compared with the corresponding area distributions of normal images to determine the presence of abnormal asymmetry. Computerized diagnoses were compared with image ratings assigned by a radiologist. The ability of the automated method to distinguish normal from asymmetrically abnormal cases was evaluated by using receiver operating characteristic (ROC) analysis, which yielded an area under the ROC curve of 0.84. This automated method demonstrated promising performance in its ability to detect abnormal asymmetry in PA chest images. We believe this method could play a role in a picture archiving and communications (PACS) environment to immediately identify abnormal cases and to function as one component of a multifaceted computer-aided diagnostic scheme. (+info)
Image processing strategies in picture archiving and communication systems.
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An image processing strategy is presented that assures very similar soft-copy presentation on diagnostic workstations of a picture archiving and communication system (PACS) over the lifetime of an image file and simultaneously provides efficient work-flow. The strategy is based on rigid partitioning of image processing into application- and display-device-specific processing. Application-specific processing is optimized for a reference display system. A description of this system is attached to the file header of the application-specifically processed image which is stored in the PACS. Every diagnostic display system automatically reproduces the image quality for which the application-specific processing was optimized by adjusting its properties by display-system-specific processing so that the system becomes effectively equal to the reference display system. (+info)
Finding-specific display presets for computed radiography soft-copy reading.
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Much work has been done to optimize the display of cross-sectional modality imaging examinations for soft-copy reading (i.e., window/level tissue presets, and format presentations such as tile and stack modes, four-on-one, nine-on-one, etc). Less attention has been paid to the display of digital forms of the conventional projection x-ray. The purpose of this study is to assess the utility of providing presets for computed radiography (CR) soft-copy display, based not on the window/level settings, but on processing applied to the image optimized for visualization of specific findings, pathologies, etc (i.e., pneumothorax, tumor, tube location). It is felt that digital display of CR images based on finding-specific processing presets has the potential to: speed reading of digital projection x-ray examinations on soft copy; improve diagnostic efficacy; standardize display across examination type, clinical scenario, important key findings, and significant negatives; facilitate image comparison; and improve confidence in and acceptance of soft-copy reading. Clinical chest images are acquired using an Agfa-Gevaert (Mortsel, Belgium) ADC 70 CR scanner and Fuji (Stamford, CT) 9000 and AC2 CR scanners. Those demonstrating pertinent findings are transferred over the clinical picture archiving and communications system (PACS) network to a research image processing station (Agfa PS5000), where the optimal image-processing settings per finding, pathologic category, etc, are developed in conjunction with a thoracic radiologist, by manipulating the multiscale image contrast amplification (Agfa MUSICA) algorithm parameters. Soft-copy display of images processed with finding-specific settings are compared with the standard default image presentation for 50 cases of each category. Comparison is scored using a 5-point scale with the positive scale denoting the standard presentation is preferred over the finding-specific processing, the negative scale denoting the finding-specific processing is preferred over the standard presentation, and zero denoting no difference. Processing settings have been developed for several findings including pneumothorax and lung nodules, and clinical cases are currently being collected in preparation for formal clinical trials. Preliminary results indicate a preference for the optimized-processing presentation of images over the standard default, particularly by inexperienced radiology residents and referring clinicians. (+info)
Challenges associated with the incorporation of digital radiography into a picture archival and communication system.
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Digital radiography (DR) has recently emerged as an attractive alternative to computed radiography (CR) for the acquisition of general radiographic studies in a digital environment. It offers the possibility of improved spatial and contrast resolution, decreased radiation dose due to improved efficiency of detection of x-ray photons, and perhaps most importantly, holds out the promise of increased technologist productivity. To achieve maximum efficiency, DR must be completely integrated into existing information systems, including the hospital and radiology information systems (HIS/RIS) and, when present, the picture archival and communication system (PACS). The early experience with the integration of DR at the Baltimore Veterans Affairs Medical Center (VAMC) has identified several challenges that exist to the successful integration of DR. DR has only recently been defined as a separate Digital Imaging and Communications in Medicine (DICOM) modality and images obtained will, at first, be listed under the category of CR. Matrix sizes with some DR products on the market exceed the current size limitations of some PACS. The patient throughput may be substantially greater with DR than with CR, and this in combination with the larger size of image files may result in greater demands for network and computer performance in the process of communication with the HIS/RIS and PACS. Additionally, in a hybrid department using both CR and DR, new rules must be defined for prefetching and display of general radiographic studies to permit these examinations to be retrieved and compared together. Advanced features that are planned for DR systems, such as dual-energy subtraction, tomosynthesis, and temporal subtraction, will likely require additional workstation tools beyond those currently available for CR. (+info)
Process reengineering: the role of a planning methodology and picture archiving and communications system team building.
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The acquisition of a picture archiving and communications system (PACS) is an opportunity to reengineer business practices and should optimally consider the entire process from image acquisition to communication of results. The purpose of this presentation is to describe the PACS planning methodology used by the Department of Defense (DOD) Joint Imaging Technology Project Office (JITPO), outline the critical procedures for each phase, and review the military experience using this model. The methodology is segmented into four phases: strategic planning, clinical scenario planning, installation planning, and implementation planning. Each is further subdivided based on the specific tasks that need to be accomplished within that phase. By using this method, an institution will have clearly defined program goals, objectives, and PACS requirements before vendors are contacted. The development of an institution-specific PACS requirement should direct the process of proposal comparisons to be based on functionality and exclude unnecessary equipment. This PACS planning methodology is being used at more than eight DOD medical treatment facilities. When properly executed, this methodology facilitates a seamless transition to the electronic environment and contributes to the successful integration of the healthcare enterprise. A crucial component of this methodology is the development of a local PACS planning team to manage all aspects of the process. A plan formulated by the local team is based on input from each department that will be integrating with the PACS. Involving all users in the planning process is paramount for successful implementation. (+info)
Electronic imaging and clinical implementation: work group approach at Mayo Clinic, Rochester.
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Electronic imaging clinical implementation strategies and principles need to be developed as we move toward replacement of film-based radiology practices. During an 8-month period (1998 to 1999), an Electronic Imaging Clinical Implementation Work Group (EICIWG) was formed from sections of our department: Informatics Lab, Finance Committee, Management Section, Regional Practice Group, as well as several organ and image modality sections of the Department of Diagnostic Radiology. This group was formed to study and implement policies and strategies regarding implementation of electronic imaging into our practice. The following clinical practice issues were identified as key focus areas: (1) optimal electronic worklist organization; (2) how and when to link images with reports; (3) how to redistribute technical and professional relative value units (RVU); (4) how to facilitate future practice changes within our department regarding physical location and work redistribution; and (5) how to integrate off-campus imaging into on-campus workflow. The EICIWG divided their efforts into two phases. Phase I consisted of Fact finding and review of current practice patterns and current economic models, as well as radiology consulting needs. Phase II involved the development of recommendations, policies, and strategies for reengineering the radiology department to maintain current practice goals and use electronic imaging to improve practice patterns. The EICIWG concluded that electronic images should only be released with a formal report, except in emergent situations. Electronic worklists should support and maintain the physical presence of radiologists in critical areas and direct imaging to targeted subspecialists when possible. Case tools should be developed and used in radiology and hospital information systems (RIS/HIS) to monitor a number of parameters, including professional and technical RVU data. As communication standards improve, proper staffing models must be developed to facilitate electronic on-campus and off-campus consultation. (+info)
The importance of a picture archiving and communications system (PACS) manager for large-scale PACS installations.
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Installing a picture archiving and communication system (PACS) is a massive undertaking for any radiology department. Facilities making a successful transition to digital systems are finding that a PACS manager helps guide the way and offers a heightened return on the investment. The PACS manager fills a pivotal role in a multiyear, phased PACS installation. PACS managers navigate a facility through the complex sea of issues surrounding a PACS installation by coordinating the efforts of the vendor, radiology staff, hospital administration, and the information technology group. They are involved in the process from the purchase decision through the design and implementation phases. They can help administrators justify a PACS, purchase and shape the request for proposal (RFP) process before a vendor is even chosen. Once a supplier has been selected, the PACS manager works closely with the vendor and facility staff to determine the best equipment configuration for his or her facility, and makes certain that all deadlines are met during the planning and installation phase. The PACS manager also ensures that the infrastructure and backbone of the facility are ready for installation of the equipment. PACS managers also help the radiology staff gain acceptance of the technology by serving as teachers, troubleshooters, and the primary point-of-contact for all PACS issues. This session will demonstrate the value of a PACS manager, as well as point out ways to determine the manager's responsibilities. By the end of the session, participants will be able to describe the role of a PACS manager as it relates to departmental operation and in partnership with equipment vendors, justify a full-time position for a PACS manager, and identify the qualifications of candidates for the position of PACS manager. (+info)