JPEG2000压缩算法及其在医学图像DICOM格式中的实现

本文描述了在医学图像DICOM格式中实现JPEG2000压缩算法的编程思路和方法.提供了部分VC++代码,对关键函数进行了较详细的注解,并对两种图像压缩格式进行了比较,给出了一个详细的实验结果.     

DICOM医学图像扩展模型的研究

医学图像存档和通讯系统PACS(Picture Archivingand Communication System)促进了医学图像的共享，但是该系统只能提供基于关键字的医学图像检索，不能进行基于语义内容检索，本研究在现有图像处理、分析和理解技术的基础上对医学图像的内容信息进行了划分，并对PACS系统的医学成像和通讯标准DICOM(Digital Imaging and Communicationin Medicine)信息模型进行了扩充，增加有关图像内容的信息，提出了DICOM信息模型的扩展模型。通过该模型来组织医学信息的存储和检索可以满足基于关键词和基于图像语义内容检索的需要，最后在该模型的框架下实现了超声心动图像基于形状特征的检索。     

联合图像专家组2000图像压缩方法的核医学应用研究

为研究联合图像专家组2000(Jo in t Photograph ic Expert G roup 2000,JPEG 2000)图像压缩方法在核医学中的应用,将无病变和有病变核医学静态图像用JPEG 2000软件压缩。对无损压缩图像,测量其压缩比。对有损压缩图像,由医生阅片,根据其结论作接收器操作特性(R ece iver operating characteristic,ROC)分析,获得各种图像压缩比的ROC曲线下的面积(A rea under curve,AUC),以其大小评价图像诊断质量;并将原始图像组AUC与各有损压缩图像组的AUC作配对t检验。实验发现,无损压缩的图像压缩比为(1.34±0.05)∶1。而有损压缩比越大,AUC越小。原始图像与压缩图像比较,压缩比为10∶1时没有显著性差异,压缩比更大时则有显著性差异。实验结果表明,无损压缩方法压缩比低,实用意义不大。有损压缩比不大于10∶1时,核医学静态图像的诊断质量得以保留。对核医学中的其它图像形式,可根据的图像性质,特别是固有统计噪声的大小,适当增减压缩比。     

DICOM医学图像的存储与管理

随着数字化医学成像设备在医院的广泛使用,对医学图像及相关数据的存档管理以及在不同科室之间的数据共享的要求越来越迫切,这就需要建立PACS(图像存档和通讯系统),这方面国外已经发展了很多年,我国目前处于起步阶段.本文参照PACS系统的一个已经被国际认可的医学图像标准即医学成像和通讯标准DICOM(digital imaging and communication in medicine),研究了标准的各个部分,特别是兼容性、信息对象定义(IOD)、服务对象对类(SOP)、数据编码等部分,就具体实现PACS系统的一个重要方面即医学图像的存档和管理做了深入的探讨,在此基础上建立了医学图像数据库系统,为实现医学图像信息的网络共享打下了基础.     

DICOM介质存储的实现技术

实用利用可移动的存储介质进行DICOM医学图像的数据存储与交换。方法提出DICOM介质存储的三层模型,基于五种基本操作和根据实际临床需要设计的两种操作,将介质存储方案分为两个模块即数据导入和数据导出。结果根据本文实现的应用软件可以实现符合DICOM标准的介质存储,并适当扩充了功能,较好地满足了医疗图像的数据存储与交换的要求。结论在实现标准的过程中,可以找到一种不同的方式,使得软件更适合临床环境,可以根据实际需要在符合标准的基础上进行功能扩充。     

JPEG2000有损压缩对核医学图像的压缩效果的客观定量研究

从线源图像获得线源扩展函数、调制转移函数和峰-总计数比等参数,定量研究JPEG 2000有损压缩对核医学图像的压缩效果,并与实际分辨率图像和模拟分辨率图像的压缩效果进行对比。实验发现,随压缩比的增加,峰-总计数比曲线逐步下降,且噪声水平越高,曲线下降越快;但调制转移函数曲线和线源扩展函数曲线的半高宽无明显变化;随压缩比的增加,分辨率图像上可辨认出的条纹逐渐减少。实验结果表明,在压缩比和噪声水平变化时,峰-总计数比的变化与图像质量的变化规律一致,是用于图像压缩效果评价的较好的客观定量参数。     

DICOM医学图像数据接口的Java实现

DICOM3.0标准作为目前通用的医学图像标准 ,最重要的特性之一在于其面向对象性。本研究依据这一重要特性 ,描述了如何使用面向对象的Java语言实现该标准的接口软件。从而解决了DICOM硬件设备与后继PACS处理软件的接口问题。同时 ,为了克服现有PACS系统的硬件瓶颈 ,对数据读入方式采取了优化 ,大大降低了CPU运行时间和内存占用空间 ,提高了系统的运行质量和性能。     

在医学图像DICOM格式中实现JPEG压缩算法

本文描述了在医学图像DICOM格式中实现JPEG压缩算法的编程思路和方法.文中提供了部分VC 代码,并对关键函数进行了较详细的注解,对同类工作具有参考价值.     

基于PACS的医学图像压缩

从PACS和DICOM的定义出发,对基于PACS的医学图像压缩的要求和算法等方面作了阐述,还介绍了JPEG2000在医学图像压缩中的优势.     

基于DICOM标准的医学图像数据库

DICOM标准是医疗影像设备信息交换的基础 ,本文依据DICOM的信息模型 ,在关系数据库的平台上 ,设计了基于DICOM标准的图像数据库。经过实验检验 ,本方案具有库结构简单 ,构造方便 ,存储效率高 ,系统扩充余地大 ,数据转换的开销小等优点。本数据库可应用在PACS、远程医疗等系统中。     

基于DICOM的医学影像设备接口设计与实现

医学影像存档与通讯系统(Picture Archiving and Communication Systems,PACS)是目前医院信息化建设的热点,医学数字成像和通信标准(Digital Imaging and Communication in Medicine,DICOM)是有关医学图像及其相关信息的数据编码及通讯的国际标准,支持DICOM标准是医学影像设备并入PACS网络的必要条件。为使目前尚不符合DICOM标准的影像设备有效并入PACS系统,必须为其添加DICOM接口。我们介绍了DICOM信息模型并实现了接口的软件系统,重点介绍了应用VisualC 编程实现DICOM服务中的C-STORE和DCM文件的读写功能。     

DICOM标准的语义扩充

医学图像数字成像和通信（Digital Imaging and Communicationsin Medicine，DICOM）标准是美国电气制造商联合会（NEMA）和美国放射学会（ACR）为了医学图像的存储和传输而制定的标准，在医学上得到广泛的应用。但该标准目前没有充分定义图像语义内容，从而使得实际中不能有效的实现DICOM的基于语义的应用。本文讨论了医学图像中的语义描述层次结构，概述了DICOM标准中对图像的描述方法并指出了该标准对图像语义内容描述的不足，给出了使用DICOM标准中私有属性对DICOM图像语义内容进行扩充的方法。     

Establishing a Web-Based DICOM Teaching File Authoring Tool Using Open-Source Public Software

Online teaching files are an important source of educational and referential materials in the radiology community. The commonly used Digital Imaging and Communications in Medicine (DICOM) file format of the radiology community is not natively supported by common Web browsers. The ability of the Web server to convert and parse DICOM is important when the DICOM-converting tools are not available. In this paper, we describe our approach to develop a Web-based teaching file authoring tool. Our server is built using Apache Web server running on FreeBSD operating system. The dynamic page content is produced by Hypertext Preprocessor (PHP). Digital Imaging and Communications in Medicine images are converted by ImageMagick into Joint Photographic Experts Group (JPEG) format. Digital Imaging and Communications in Medicine attributes are parsed by dicom3tools and stored in PostgreSQL database. Using free software available from the Internet, we build a Web service that allows radiologists to create their own online teaching file cases with a common Web browser.     

DICOM for Clinical Research: PACS-Integrated Electronic Data Capture in Multi-Center Trials

Providing surrogate endpoints in clinical trials, medical imaging has become increasingly important in human-centered research. Nowadays, electronic data capture systems (EDCS) are used but binary image data is integrated insufficiently. There exists no structured way, neither to manage digital imaging and communications in medicine (DICOM) data in EDCS nor to interconnect EDCS with picture archiving and communication systems (PACS). Manual detours in the trial workflow yield errors, delays, and costs. In this paper, requirements for a DICOM-based system interconnection of EDCS and research PACS are analysed. Several workflow architectures are compared. Optimized for multi-center trials, we propose an entirely web-based solution integrating EDCS, PACS, and DICOM viewer, which has been implemented using the open source projects OpenClinica, DCM4CHEE, and Weasis, respectively. The EDCS forms the primary access point. EDCS to PACS interchange is integrated seamlessly on the data and the context levels. DICOM data is viewed directly from the electronic case report form (eCRF), while PACS-based management is hidden from the user. Data privacy is ensured by automatic de-identification and re-labelling with study identifiers. Our concept is evaluated on a variety of 13 DICOM modalities and transfer syntaxes. We have implemented the system in an ongoing investigator-initiated trial (IIT), where five centers have recruited 24 patients so far, performing decentralized computed tomography (CT) screening. Using our system, the chief radiologist is reading DICOM data directly from the eCRF. Errors and workflow processing time are reduced. Furthermore, an imaging database is built that may support future research.     

Benefits of the DICOM Structured Report

Recently, the digital imaging and communications in medicine (DICOM) standard introduced rules for the encoding, transmission, and storage of the imaging diagnostic report. This medical document can be stored and communicated with the images in picture archiving and communication system (PACS). It is a structured document that contains text with links to other data such as images, waveforms, and spatial or temporal coordinates. Its structure, along with its wide use of coded information, enables the semantic understanding of the data that is essential for the Electronic Healthcare Record deployment. In this article, we present DICOM Structured Report (SR) and discuss its benefits. We show how SR enables efficient radiology workflow, improves patient care, optimizes reimbursement, and enhances the radiology ergonomic working conditions. As structured input significantly alters the interpretation process, understanding all its benefits is necessary to support the change. Biography Rita Noumeir is a professor at the Department of Electrical Engineering of the University of Quebec, école de Technologie Superieure in Montreal. A founding member of the Imaging, Vision, and Artificial Intelligence Laboratory (LIVIA), her main research interest is the Healthcare Information Technology, specifically, Interoperability, Electronic Patient Record, Security, Information Confidentiality, and Image Processing. As a member of both Technical and Planning International IHE Radiology Committees, Dr. Noumeir took part over the last 5 years in developing many Integrating the Healthcare Enterprise (IHE) Integration Profiles in Radiology and in organizing several Integration Demonstrations. She is a cofounder of IHE Canada. Dr. Noumeir contributed to many research and development projects in collaboration with several Canadian and international companies in medical imaging and healthcare information. Currently, she collaborates with the Diagnostic Imaging Team of Canada Health Infoway to define the principles and architecture for sharing imaging information between multiple healthcare institutions. She plays a leading role in the development of this solution that is published as an IHE Integration Profile for which she is the editor. Rita Noumeir holds a Ph.D. and a Masters degree in Biomedical Engineering from école Polytechnique of Montreal specializing in Medical Imaging. She is a professional engineer, and a member of the Ordre des ingénieurs du Québec.     

基于DICOM标准的TLS网络安全传输技术研究与实现

随着医疗信息化的发展,图像归档与通信系统(PACS)、医院信息系统/放射科信息系统(HIS/RIS)等医疗信息管理系统日渐普及和完善,这些系统之间的互操作越发频繁,通过网络由一个封闭的系统走向开放,走向区域化成为必然。而信息的传输安全是使之成为可能的前提条件。基于网络安全的必要性,着重研究了医学数字成像与通信(DICOM)标准和安全传输层(TLS)协议,并结合OpenSSL工具包和DCMTK工具包实现了DICOM医疗信息TLS安全传输。     

Teaching DICOM by Problem Solving

The Digital Imaging and Communications in Medicine (DICOM) is the standard for encoding and communicating medical imaging information. It is used in radiology as well as in many other imaging domains such as ophthalmology, dentistry, and pathology. DICOM information objects are used to encode medical images or information about the images. Their usage outside of the imaging department is increasing, especially with the sharing of medical images within Electronic Health Record systems. However, learning DICOM is long and difficult because it defines and uses many specific abstract concepts that relate to each other. In this paper, we present an approach, based on problem solving, for teaching DICOM as part of a graduate course on healthcare information. The proposed approach allows students with diversified background and no software development experience to grasp a large breadth of knowledge in a very short time.