一个miniPACS的设计与实现

医学图像归档及通信系统(PACS)的设计与实现是医学图像处理及传输领域的研究热点。本文分析和探讨了如何基于一家医院的CT科室的现有设备(比如CT、MR等)来设计和实现一个小型PACS(miniPACS)。这里,我们结合自行开发的图像归档服务器,采用医学数字成像及通信标准——DICOM3.0作为底层互操作平台,构建了这个miniPACS,并且实现了图像归档、图像查询/提取、图像打印以及图像的后处理等功能。     

基于小波多尺度边缘的图像归档和查询

通过对基于图像内容的查询以及医学图像数据库领域知识的研究，提出了基于小波多尺度边缘的尺度综合和模拟人类视觉心理学特点的医学图像归档及查询方法。对基于内容的查询的检验标准进行了讨论。构造了一个基于日常临床医学图像数据库的图像归档与通信系统(PACS)的原型系统。在此系统上对上述算法进行了试验，结果证明了该算法的有效性和可行性。     

医学图像存档及通信系统的设计与实现

医学图像存档及通信系统(PACS)的设计与实现是医学图像处理及传输领域的研究热点本文分析和探讨了一个miniPACS 设计和实现。我们结合自行开发的图像存档服务器,基于医学数字成像及通信标准DICOM3.0, 构建了这个miniPACS, 实现了图像存档,图像查询/提取图像打印以及图像的后处理等功能。     

DICOM格式CT图像的数据库存储技术

图像归档与传输系统(PACS)因其重要性倍受医学界与计算机界的关注。但是，目前实际应用的PACS都是基于文件系统的，即DICOM图像以文件的形式存储。这样的PACS系统有许多缺点，例如，查询某幅指定DICOM图像的信息比较困难；文件与相关数据库记录的一致性很难维护；网络传输效率低等。文中提出了一种存储技术，以解决传统PACS的上述问题。     

PACS图像存档及传输的管理技术

介绍了PACS中医学图像的管理流程,重点阐述了PACS系统中图像在各个功能模块中及功能模块间存储及传输的有效管理方法,着重对PACS中医学图像的预提取及预分配技术进行了研究,提出了利用套接字实现网关工作站与科室图像服务器之间的消息通讯,利用FTP机制实现文件传输的预提取实现方案.试验结果表明这种预提取机制可以有效提高整个PACS运行效率.     

PACS设计与实现中的几个关键问题

医学图像归档及通信系统（PACS）的设计与实现是医学图像处理领域的研究热点,同时对医院构建放射学信息系统、医院信息系统有着重要意义。结合开发图像归档服务器的经验,分析和探讨了PACS设计和实现中的几个关键问题,比如PACS的功能选择、PACS底层通信协议的选择、数据库的管理、图像存储媒体的选择、图像诊断工作站的选择、支持远程医疗的WEB数据发布策略等等。最后,阐述了一个新构建的小型PACS的机构和主要技术。     

GY-2 PACS中DICOM网关的设计与实现

DICOM协议是医学影像系统PACS中被广泛采用的标准，但目前医学图像数据源中很多是非DICOM标准的。文章结合广州医学院附属第二医院PACS实践经验，设计并实现了DICOM网关，将非DICOM图像融入PACS中，对于PACS的实现具有重要的意义。     

基于DCM4CHEE的PACS审计子系统的设计与实现

本文研究基于消息和面向服务的开源PACS系统--DCM4CHEE的设计方法和系统架构,使用MySQL和JBoss搭建实验的PACS系统.重点设计和完善审计子系统,采用SpringMVC&Hibernate框架和Servlet技术,实现审计记录删除;采用Criteria技术实现检索审计记录和限定条件的统计查询;通过JSF技术构建Web程序显示查询和统计结果.本文最终实现完善了的审计子系统.     

PACS应用研究

本文论述了传统医学图像保存和处理方式存在的问题及PACS的主要特点，并就PACS的几种开发模型及其相关的关键技术进行了分析、研究，以期对PACS的开发及应用有所借鉴和帮助。     

基于PACS的计算机手术导航过程归档

为了实时而高效地记录整个手术导航执行过程,提出基于PACS的计算机手术导航过程归档技术,通过在手术过程中实时采集能够反映整个手术过程的图像和位置坐标数据,并将这些图像和坐标数据转换为PACS系统能够支持的DICOM文件,进而存入PACS系统数据库中,实现手术过程的记录,通过数据提取从PACS系统中获得手术过程的原始数据,并依据获得的原始图像和位置坐标数据回放和还原整个手术导航过程,完成手术导航过程的归档。     

基于DICOM标准的大型医学影像分布式存储系统研究

提出了一种符合DICOM标准的大型医学影像分布式存储系统的体系结构。采用多级分布式存储体系，引入JPEG2000压缩技术，结合大型数据库，实现智能、稳定和高效的存储管理。切实解决了医院影像中心PACS目前和未来对大容量／超大容量医学影像数据存储的需求。     

FOCUS: A system for searching for multi-colored objects in a diverse image database

We describe a new multi-phase, color-based image retrieval system (FOCUS) which is capable of identifying multi-colored query objects in an image in the presence of significant, interfering backgrounds. The query object may occur in arbitrary sizes, orientations, and locations in the database images. Scale and rotation invariant color features have been developed to describe an image, such that the matching process is fast even in the case of complex images. The first phase of processing matches the query object color with the color content of an image computed as the peaks in the color histogram of the image. The second phase matches the spatial relationships between color regions in the image with the query using a spatial proximity graph (SPG) structure designed for the purpose. Processing at coarse granularity is preferred over pixel-level processing to produce simpler graphs, which significantly reduces computation time during matching. The speed of the system and the small storage overhead make it suitable for use in large databases with online user interfaces. Test results with multi-colored query objects from man-made and natural domains show that FOCUS is quite effective in handling interfering backgrounds and large variations in scale. The experimental results on a database of diverse images highlights the capabilities of the system.     

Clinical application of a magneto-optical disk image filing system/image save and carry (ISAC) system.

We propose the utilization of portable magneto optical disks for image filing. The main problems in PACS are the need for a high-speed local area network (LAN) and a large mass storage device. An image filing system--image save and carry (ISAC)--is one solution for these problems in present PACS and requires minimal additional hardware and cost for the installation. Whenever a patient is examined, the clerk carries the medical record and the ISAC magneto-optical disk for recording image data, and after inspection records the image data into the magneto-optical disk. We investigated the number of image retrievals done for inpatients and outpatients in 1988 at our radiation therapy department. The data storage requirements were on the average 18.5 MB for outpatients and 173.9 MB for inpatients. An ISAC display console needs also an easy-to-use man/machine interface for specifying images and image display characteristics in order to realize the ISAC system.     

Content-based facial image retrieval using constrained independent component analysis

Content-based image retrieval (CBIR) is a method of searching, browsing, and querying images according to their content. In this paper, we focus on a specific domain of CBIR that involves the development of a content-based facial image retrieval system based on the constrained independent component analysis (cICA). Originating from independent component analysis (ICA), cICA is a source separation technique that uses priori constraints to extract desired independent components (ICs) from data. By providing query images as the constraints to the cICA, the ICs that share similar probabilistic features with the queries from the database can be extracted. Then, these extracted ICs are used to evaluate the rank of each image according to the query. In our approach, we demonstrate that, in addition to a single image-based query, a compound query with multiple query images can be used to search for images with compounding feature content. The experimental results of our CBIR system tested with different facial databases show that our system can improve retrieval performance by using a compound query. Furthermore, our system allows for online processing without the need to learn query images.     

Study on the technology of medical image reading based on JPEG2000

Along with the development of health informatization, many hospitals have set up PACS systems for centralized storage of patients’ medical examination images. Due to the large amount of image data, traditional methods such as C-MOVE, have slow upload and download speeds. And they also have security problems. Based on the research and development of medical imaging informatics and PACS, a JPEG2000-based method is described according to the PACS work flow and DICOM standard. This method makes the image storage, transmission and display operating in parallel, providing a good solution to timeliness and security problems of image reading and viewing.     

Experience of a small PACS in Tottori University Hospital.

Picture archiving and communications systems (PACS) are expected to become feasible as the way of total radiologic image management. As the first step towards computerized image management, we installed an experimental small PACS with a digital optical archive for magnetic resonance and digitized radiographic film images. During the first 10 months of operation, problems were caused by the frequent mechanical troubles on the acquisition devices, impractical schemes for transmission, and troublesome retrieval and display of images. Although some of them have been solved by the improvements of both hardware and software, the mechanical instability of the digitizer and the inadequate operating procedure of the workstation still remain. As to the characteristics of PACS, the capability of access to every achieved radiologic image is the great advantage for us because the image integration has been impossible in the form of radiographic films for the traditional image management system of our hospital. However, the complicated image display procedure with high overheads is far from ideal for radiologists. The efficiency of image display must be increased to the level of a conventional film viewing system. Furthermore, research is needed on the small PACS to get consensus for the acceptance of a more widely implemented system.     

基于HBase的遥感数据分布式存储与查询方法研究

遥感影像的存储与查询是地理信息处理中重要的内容,在海量遥感影像的实时处理中发挥着重要作用。针对传统的遥感影像处理中存在单节点故障、扩展性低和处理效率低等问题,提出了一种基于HBase的遥感数据分布式存储与查询方案。该方法首先采用均匀网格对遥感影像进行划分,并根据划分结果设计了一种基于网格ID和Hilbert曲线相结合的索引方案。然后,通过利用HBase的过滤机制设计了过滤列族,达到了在查询时筛选数据的目的。另外,采用MapReduce的并行处理方法对影像数据进行并行写入和查询。实验结果表明,与MySQL和MapFile相比,该方法可以有效地提高数据的写入和查询速度,且具有较好的可扩展性。     

基于语义学习的图像多模态检索

针对语义鸿沟问题,在语义学习的基础上设计图像的多模态检索系统。该系统结合3种查询方式进行图像检索。基于视觉特征的查询通过特征提取与相似度匹配进行排位。基于标签的查询建立在图像自动标注的基础上,但在语义空间之外的泛化能力较差。基于语义图例的查询能够在很大程度上克服这个缺陷,通过在显式或隐式的语义空间上进行查询,使检索结果更符合人类感知。实验结果表明,与基于纹理特征的图像检索相比,基于语义图例的检索具有更高的精度及召回率。     

Expert system for color image retrieval

Recently, as Web and various databases contain a large number of images, content-based image retrieval (CBIR) applications are greatly needed. This paper proposes a new image retrieval system using color-spatial information from those applications.First, this paper suggests two kinds of indexing keys to prune away irrelevant images to a given query image: major colors' set (MCS) signature related with color information and distribution block signature (DBS) related with spatial information. After successively applying these filters to a large database, we get only small amount of high potential candidates that are somewhat similar to a query image. Then we make use of the quad modeling (QM) method to set the initial weights of two-dimensional cell in a query image according to each major color. Finally, we retrieve more similar images from the database by comparing a query image with candidate images through a similarity measuring function associated with the weights. In that procedure, we use a new relevance feedback mechanism. This feedback enhances the retrieval effectiveness by dynamically modulating the weights of color-spatial information. Experiments show that the proposed system is not only efficient but also effective.     

Atlas: a nested relational database system for text applications

Advanced database applications require facilities such as text indexing, image storage, and the ability to store data with a complex structure. However, these facilities are not usually included in traditional database systems. In this paper we describe Atlas, a nested relational database system that has been designed for text-based applications. The Atlas query language is TQL, an SQL-like query language with text operators. The query language is supported by signature file text indexing techniques, and by a parser that can be configured for different text formats and even some foreign languages. Atlas can also be used to store images and audio