Computer-assisted radiology

New digital imaging modalities and more sophisticated image processing systems will have a profound effect on those areas of medicine concerned with imaging. This mainly means computer-assisted radiology (CAR) and implies a transition from analog film systems to digital imaging systems, integration of digital imaging modalities through picture archiving and communication systems (PACS) and the graduated employment of image-oriented medical work stations (MWS) for computer-assisted representation, communication, diagnosis, and therapy planning.     

PACS系统的构建及临床应用

目的:通过构建PACS(picture arhiving and communication system,PACS)系统,探讨其临床应用价值。方法:采用上海汇硕智能科技有限公司开发的VISUN3.1软件,使影像信息数据服务器与各影像设备、诊断报告工作站、登记工作站、科室管理工作站、激光相机和医院影像站点,通过交换机连接成网络。结果:PACS系统实现了影像诊断设备的网络化、影像信息的数字化、医院管理的规范化,实现了影像信息的共享,使医学影像的采集、存储、传输、及图像处理变为现实。结论:PACS系统为医学影像的存储、传输、处理提供了便利,提高了影像科的工作效率,方便了工作、教学、科研和会诊,为建设数字化医院,打下了良好的基础。     

The digital imaging workstation

Picture archiving and communication systems (PACS) are expected to convert film-based radiology into a computer-based digital environment, with associated cost savings and improved physician communication. The digital workstation will be used by physicians to display these "soft-copy" images; however, difficult technical challenges must be met for the workstation to compete successfully with the familiar viewbox. Issues relating to image perception and the impact on physicians' practice must be carefully considered. The spatial and contrast resolutions required vary according to imaging modality, type of procedure, and class of user. Rule-based software allows simple physician interaction and speeds image display. A consensus appears to be emerging concerning the requirements for the PACS workstation. Standards such as the American College of Radiology/National Electrical Manufacturers' Association Digital Imaging and Communication Standard are facilitating commercial applications. Yet much careful study is needed before PACS workstations will be fully integrated into radiology departments.     

Medical image security in a HIPAA mandated PACS environment.

Medical image security is an important issue when digital images and their pertinent patient information are transmitted across public networks. Mandates for ensuring health data security have been issued by the federal government such as Health Insurance Portability and Accountability Act (HIPAA), where healthcare institutions are obliged to take appropriate measures to ensure that patient information is only provided to people who have a professional need. Guidelines, such as digital imaging and communication in medicine (DICOM) standards that deal with security issues, continue to be published by organizing bodies in healthcare. However, there are many differences in implementation especially for an integrated system like picture archiving and communication system (PACS), and the infrastructure to deploy these security standards is often lacking. Over the past 6 years, members in the Image Processing and Informatics Laboratory, Childrens Hospital, Los Angeles/University of Southern California, have actively researched image security issues related to PACS and teleradiology. The paper summarizes our previous work and presents an approach to further research on the digital envelope (DE) concept that provides image integrity and security assurance in addition to conventional network security protection. The DE, including the digital signature (DS) of the image as well as encrypted patient information from the DICOM image header, can be embedded in the background area of the image as an invisible permanent watermark. The paper outlines the systematic development, evaluation and deployment of the DE method in a PACS environment. We have also proposed a dedicated PACS security server that will act as an image authority to check and certify the image origin and integrity upon request by a user, and meanwhile act also as a secure DICOM gateway to the outside connections and a PACS operation monitor for HIPAA supporting information.     

医学影像存档与通信系统(PACS)的应用体会

目的介绍了胜利油田中心医院医学影像存档与通信系统(PACS)应用的体会。方法把具有医学数字成像及通信(digital imaging and communication in medicine)影像设备连接成医院的PACS系统；将传统的胶片存储模式与现代的PACS管理系统相比较。结果传统的胶片存储模式在影像和管理与存储上存在种种弊端，PACS系统实现了统一存储和资源共享。结论PACS的应用明显提高了放射科及相关科室的工作效率，方便了工作、教学、科研和会诊，提高了医院的社会效益和经济效益。     

医学影像存档与通讯系统的开发与初步应用

目的 通过组建简便医学影像存档与通讯系统（ｐｉｃｔｕｒｅ ａｒｃｈｉｖｉｎｇ ａｎｄ ｃｏｍｍｕｎｉｃａｔｉｏｎ ｓｙｓｔｅｍｓ,ＰＡＣＳ）实现影像诊断设备的网络化,诊断报告书写计算机化,标准化。方法 ＣＴ,ＭＲＩ和Ｓｕｎ Ａｄｖａｎｔａｇｅ Ｗｉｎｄｏｗｓ１２．０工作站连接成医学数字影像传输（ＤＩＣＯＭ）网络;ＤＩＣＯＭ 与各图像浏览及诊断报告书写终连接成以太网网络;二者再通过集线器连接成ＰＡＣ     

DICOM demystified: a review of digital file formats and their use in radiological practice

Digital imaging and communications in medicine (DICOM) is the standard image file format used by radiological hardware devices. This article will provide an overview of DICOM and attempt to demystify the bewildering number of image formats that are commonly encountered. The characteristics and usefulness of different image file types will be explored and a variety of freely available web-based resources to aid viewing and manipulation of digital images will be reviewed. How best to harness DICOM technology before the introduction of picture archiving and communication systems (PACS) will also be described.     

Financing a large-scale picture archival and communication system

RATIONALE AND OBJECTIVES: An attempt to finance a large-scale multi-hospital picture archival and communication system (PACS) solely based on cost savings from current film operations is reported. MATERIALS AND METHODS: A modified Request for Proposal described the technical requirements, PACS architecture, and performance targets. The Request for Proposal was complemented by a set of desired financial goals-the main one being the ability to use film savings to pay for the implementation and operation of the PACS. RESULTS: Financing of the enterprise-wide PACS was completed through an operating lease agreement including all PACS equipment, implementation, service, and support for an 8-year term, much like a complete outsourcing. Equipment refreshes, both hardware and software, are included. Our agreement also linked the management of the digital imaging operation (PACS) and the traditional film printing, shifting the operational risks of continued printing and costs related to implementation delays to the PACS vendor. An additional optimization step provided the elimination of the negative film budget variances in the beginning of the project when PACS costs tend to be higher than film and film-related expenses. CONCLUSION: An enterprise-wide PACS has been adopted to achieve clinical workflow improvements and cost savings. PACS financing was solely based on film savings, which included the entire digital solution (PACS) and any residual film printing. These goals were achieved with simultaneous elimination of any over-budget scenarios providing a non-negative cash flow in each year of an 8-year term.     

Hospital-wide distribution of nuclear medicine studies through a broadband digital network

Nuclear medicine provides a good environment for the evaluation of picture archiving and communication systems (PACS) because of the relatively small quantity of digital data that are generated, leading to reduced requirements for storage, display, and transmission compared with those found in radiology. The PACS in nuclear medicine is characterized by use of a single computer as a central storage, display, and analysis node. Images are acquired with use of small, low-cost computers attached to each camera. This network configuration offers advantages of convenience, but with great reliance on a single computer. A campus-wide picture network is under development at Washington University employing broadband cable television technology supplemented by baseband Ethernet (Digital Equipment Corp, Maynard, MA) components. All areas of diagnostic radiology and nuclear medicine are connected via a PACS testbed project. A radiology information system, supporting over 250 terminals, provides digital tracking of patients and report generation and retrieval. A new image workstation is under development in conjunction with Digital Equipment Corp. This system will permit display in multiple windows of report information and images from various modalities. A lung scan demonstration project is now beginning that is designed to test the value of a PACS in nuclear medicine. Digitally acquired chest radiographs will be displayed on an image workstation in nuclear medicine along with digital ventilation and perfusion lung scans. It is hoped that time-consuming logistic bottlenecks now encountered in lung scan interpretation will be reduced.     

An economical, personal computer-based picture archiving and communication system.

Taichung Veterans General Hospital has been developing a hospital-wide picture archiving and communication system (PACS) since 1993. A personal computer-based environment was implemented to reduce costs (only $2,500 for each view station) and take advantage of distributed system techniques. Other features of the PACS are automatic image acquisition, hierarchic storage management, efficient image transmission, robust fault tolerance, and user-friendly image manipulation. The system is integrated with the hospital information system so that Chinese-language patient data can be automatically transferred. A four-tier storage hierarchy and a multipath search strategy are used to improve reliability and efficiency. Image compression and efficient image transmission techniques (autorouting and prefetching) are used to reduce the response time. Robust fault tolerance is achieved with fault-tolerant hardware, image replication, and a system watchdog. User-friendly image manipulation features include easy adjustment of the brightness, contrast, or quality of the displayed image; several windows for image display; and image measurement capability. The PACS currently supports computed tomography, ultrasound, magnetic resonance imaging, computed radiography, and digital fluoroscopy; almost all appropriate personal computers in the hospital can be used as view stations. Users are satisfied with the quality, reliability, and performance of the system.     

Digital imaging and picture archiving and communication systems

Great progress has been made in digital imaging of the chest. Most studies are dealing with computed radiography. Chest radiography in the intensive care unit may, in most cases, be performed using computed radiography. However, subtle pulmonary interstitial disease can be demonstrated less confidently using computed radiography. Significantly better detection of calcified lung nodules can be obtained by using simplified single-exposure dual-energy technique that uses storage phosphor. The wide latitude of computed radiography permits images of high quality in areas other than chest radiography. Encouraging results are presented especially in the diagnostic evaluation of scoliosis and other musculoskeletal abnormalities. An important technical innovation in digital radiography is an improved method for single-exposure dual-energy digital imaging using prefiltration with gadolinium, a cassette consisting of four photostimulable phosphor plates, spatially dependent scatter and beam hardening corrections, and noise reduction algorithm. Other groups tested algorithms for enhancement of digital images that allowed significant data compression. The implementation of picture archiving and communication systems (PACS) is inevitable; the question concerning PACS implementation is not why, but when. A comparison of the cost-effectiveness of PACS with conventional film archiving and communication systems shows that PACS should provide indirect savings when regarding the hidden costs of conventional systems. Much more experience will be needed before there is general agreement on the best design for the radiologist's workstation. Teleradiology should contribute to radiologic consultation for remote locations, because it improves the efficacy of management of patients in such locations.     

Software suite for image archiving and retrieval.

The efficient operation of a clinical picture archiving and communication system (PACS) requires a fully functional image archive. The archive should not only be able to store and retrieve images reliably but should also work in concert with software that optimizes the flow of image-related information throughout the PACS. The authors devised a software suite that serves to improve the flow and content of information and the integrity of the data. The software was developed by translating the functions performed by a conventional film library. Types of transactions possible with this system include scheduling, canceling, rescheduling, and prestaging examinations; changing demographic information; merging patient information; and generating reports. The authors believe such a software suite is essential for a clinically useful PACS.     

Integration of computer assisted bone age assessment with clinical PACS.

Computer assisted bone age assessment (BAA) integrated with a clinical PACS is described. The image analysis is performed on a DICOM compliant workstation able to accept images from a PACS server or directly from an image modality (digital radiography or film scanner). Images can be processed in two modes. If the image is acquired from a normally developed subject, it can be added to the digital hand atlas. An image may also be subjected only to a diagnostic analysis for the BAA without archiving the features in the database. The image analysis is performed in three steps. A location of six region of interest is followed by their segmentation and feature extraction. The features analysis results in retrieving the closest image match from the standard database. Based on currently analyzed image data in the hand atlas, the standard deviation of the assessment bone age does not exceed 1 yr of age.     

Film-free efficiency systems: a new cost-effective approach

Pressure is on healthcare providers to make their services more affordable. Streamlining operations to improve efficiency is one means of achieving that goal. PACS has been touted as the technology to improve radiologic services. Sold as a way to eliminate lost records and lower operations costs, in reality, PACS has raised costs and slowed work flow in many cases. Perhaps PACS that raise operations costs are more properly named digital overhead generating systems (DOGS). There is an alternative solution--film-free efficiency systems (FFES), defined as the technological tools required to lower radiologic costs and improve services. A new type of image and information management technology and distinct from traditional PACS in a number of ways, film-free efficiency systems are immediately cost effective. They improve personnel efficiency, reduce costs per RVU, provide an alternative to film and exclude the use of any technology that is not cost effective. Implementation of these systems must begin with a clearly stated mission, a leadership statement and financial accountability. To guarantee an immediate financial gain in your department, you'll want to finance the system through material cost savings. Implementation should start with the digital modalities. The next step is to retrain staff and reengineer the workplace, followed by creating the necessary infrastructure of PCs in referring physicians' offices. Lastly, implement CR or digital radiography as prices drop and technologies improve in speed.     

Enterprise-wide PACS: beyond radiology, an architecture to manage all medical images

RATIONALE AND OBJECTIVES: Picture archiving and communication systems (PACS) have the vocation to manage all medical images acquired within the hospital. To address the various situations encountered in the imaging specialties, the traditional architecture used for the radiology department has to evolve. MATERIALS AND METHODS: We present our preliminarily results toward an enterprise-wide PACS intended to support all kind of image production in medicine, from biomolecular images to whole-body pictures. Our solution is based on an existing radiologic PACS system from which images are distributed through an electronic patient record to all care facilities. This platform is enriched with a flexible integration framework supporting digital image communication in medicine (DICOM) and DICOM-XML formats. In addition, a generic workflow engine highly customizable is used to drive work processes. RESULTS: Echocardiology; hematology; ear, nose, and throat; and dermatology, including wounds, follow-up is the first implemented extensions outside of radiology. CONCLUSION: We also propose a global strategy for further developments based on three possible architectures for an enterprise-wide PACS.     

Integration of multiple direct digital imaging sources in a picture archiving and communication system (PACS)

OBJECTIVES: The aim of this report was to describe a flexible picture archiving and communication system (PACS) able to handle and communicate digital image data from various radiography systems and other sources. METHODS: The radiographic image is acquired using the vendor's own software. Following image capture, a "request for update" message (appending a record to an Access database) activates our PACS engine, "DigiMerge". Images from sources with no patient-related organizing software, e.g. TWAIN-compatible scanners and digital cameras, are handled by a self-developed program, "MedCom-T". DigiMerge generates and maintains one database based on all manufacturers' databases (software: VixWin 2000, Digora for Windows, Dimaxis Pro, Sidexis, CDR DICOM for Windows, Trophy for Windows). This database contains patient information, image information and image path. The program "DigiView" searches a patient and displays patient and image data from the database generated by DigiMerge. With DigiView, images can be viewed at any workstation in the dental school, but only temporary changes can be made (contrast, brightness, etc.) and no image can be deleted. RESULTS: The PACS is currently installed on 86 workstations. Statistics collected by DigiMerge reveal that approximately 2000 new digital images are recorded each month, half of which are radiographs and the other half are clinical photographs. Statistics collected by DigiView reveal that 500-800 digital images are opened per week. CONCLUSIONS: The self-developed PACS is able to manage images from a range of digital modalities each providing its own image data format.     

通过工作列表实现数字化网络各系统之间患者信息的一致性

目的 实现图像存储与传输系统(picture archiving and communication system，PACS)、放射学信息系统(radiology information systems，RIS)、影像设备之间患者检查信息的一致性。方法 我院引进GE Signa 1．5T磁共振、数字乳腺，Agfa数字X线摄影、计算机X线摄影及GE CT等数字化医学设备。GE PACS是英文系统，所以前期医院在未解决信息一致性时只通过PACS对检查影像进行保存，通过PACS系统中简单的信息管理工作，并没有真正意义上的worklist。2个月后，我院采用国际上先进的解决方法即通过医学数字成像及通讯(digital imaging and communication in medicine，DICOM)标准的工作列表(worklist)的方法实现信息的一致性。在RIS系统中将患者中文信息转换为英文信息，保存并为worklist提供患者的英文信息。结果 我院在集成PACS和RIS的2年多时间以来，通过worklist来保证RIS与影像设备患者检查信息的一致性，取得了非常好的效果。在所有诊断工作站上，诊断医生通过中文RIS系统，对病人的信息进行编辑、修改、产生。结论 通过worklist实现PACS、RIS、影像设备之间患者检查信息的一致性是可行的。     

Comparison of full-field digital mammography workstation and conventional picture archiving and communication system in image quality and diagnostic performance

The object of this study was to compare of full-field digital mammography (FFDM) workstation and conventional picture archiving and communication systems (PACS) in image quality and diagnostic performance. We assembled 80 masses and 80 microcalcifications. Images were displayed on workstation, 5M, and 3M PACS monitors. The image quality for mammograms on workstation was significantly better than that for mammograms on PACS monitors. The sensitivity and NPV for microcalcifications on workstation were higher than those on PACS monitors. The conventional PACS cannot substitute for a FFDM workstation for mammographic evaluation.     

图像存储与传输系统的总体设计与分步实施

目的 探讨在组建图像存储与传输系统（picture archiving and communication system,PACS)过程中的总体设计及如何进行具体每一步的实施方案。方法 把具有医学数学成像及通讯（digital imaging and communication in medicine,DICOM)标准接口或非DICOM标准接口的影像设备进行联网，制定资源共享、系统存储的解决方案，建立典型的医院放射科PACS系统，连接目前医院现有的设备，服务器采用Windows NT SQL Server 7.0组成，解决管理及存储问题，工作站基于浏览（WEB）方式访问，扩大客户端的使用权限（license)，数量为100个，磁盘阵列（RAID 5）在线存储3个月，线性磁带库（DLT)离线海量存储；扩展全院并解决放射学信息系统（radiology information systems,RIS)、PACS的数据共享连接；建立地区影像数据交换中心。结果 建立了典型的医院放射科PACS系统，连接了目前医院现有的设备，实现了放射科初步的无胶片化方式；将PACS扩展到了全院的临床科室、手术室、急诊室等，以及实现了和已有的医院信息系统（hospital information systems,HIS)、其他医院网络联网，建立起了影像数据中心；实现了和本地区其他医院及其他地区的影像数据中心的联网，使用起来较为得心应手，方便了医生，提高了工作效率。结论 实践证明，上述PACS的总体设计与分步实施方案是可行的、成功的。