【作者】 黄昊；

【导师】 孙景琪；

【作者基本信息】 北京工业大学 ， 电路与系统， 2000， 硕士

【摘要】 当前，各种医学影像设备如X光机、CT、核磁共振仪等已愈来愈多的进入医院，医学影像胶片正在以爆炸式的速度增长。得益于计算机和多媒体等信息技术的迅猛发展，PACS系统已不仅仅停留在概念阶段，而是正在向实用化、大众化方向发展。这使得医学影像的数字化存储正在逐渐成为现实。在我国，PACS系统的国产化和低成本化是各生产厂家、研究机构的研发热点。 本文首先较全面的介绍了PACS系统的各个方面：①系统的产生、现状和发展趋势；②对PACS系统所涉及的主要技术做了详细的介绍，如医学图像的压缩技术和多媒体数据库等关键技术；③分组件模块介绍了系统的一般构成；④介绍了评估系统效益的3个模型。 第二章重点阐述了对医学图像压缩技术的研究及所进行的工作。在分析对比了几种广泛实用的无损与有损压缩方法的基础上，针对医学图像有损压缩的总体趋势，提出了一种有损与无损方法相结合的、有较高保真度的压缩方法：分区压缩方法。实验结果表明该方法适于医学图像的有损压缩，在得到较高压缩比的同时，完整的保留了病灶区信息，不会对诊断造成负面影响。 第三章对PACS系统的数据库技术进行了探讨。详细介绍了利用扩充型关系数据库，采用客户/服务器模式建立基于SQL Server 7.0的PACS归档数据库。为减低系统硬件成本，对PACS系统的三级归档存储方式进行了改进。将高速缓存及一级归档均存储于同一存储介质—归档服务器中。 第四章从系统集成角度详细介绍了Micro-PACS系统的设计方案。给出了基于PC平台的PACS组件集成方案和系统管理软件整体设计方案。就其中的数字图像处理模块中两中常用的图像显示技术：图像增强和图像局部放大进行了研究与实验。更多还原

【Abstract】 Currently, many modalities such as computed tomography(CT), magnetic resonance imaging(M1RI) are playing important role in modem hospital. They produce more and more images films. The concept of PACS, profit from repid development of computer science & information technology, has became a more applied and popular hospital’s equipment. Along with PACS, the digital storage of medical image has come into ture reality. In our country, the hot focus of research institution and manufacturers is localizing PACS and reducing the costs of PACS. In this paper, primarily, the writer introduce the PACS system in details. It includes the need for PACS, the trend of PACS. Also it lists some involved fields of thchnology in PACS, such as digital image compression, image storage database, image transmission and so on. The components of PACS are descripted at following. Then we introduce 3 modules of evaluating PACS benefit. In second part of paper, we emphasize in research of medical image compression technology. The trend in medical image compression is increasingly toward lossy compression. Based on it, we develop a kind method of combining lossless and lossy compression. It is called divisional compression. This method is a lower distortion compression. We split the medical image into 3 parts: the erea of focus of a disease, the constructional area and the background area. Different comression methods are used aiming at each area. The compression ratio is relatively high for low distortion. In chapter 3, we discuss the multi-media database technology for PACS. A demo image database and case history database are established using SQL Server 7.0. Also client/server mode is involved. In chapter 4, we particularly introduce the Micro-PACS system integrated solution, including hardware and software. Further more, two kinds of Image Enhancing mathod are discussed and we shows some results of using digital image processing.更多还原