面向临床研究主题服务的医学影像数据库研制

研制面向临床研究主题服务的医学影像数据库,建立数据库制作流程,实现医学影像按疾病分类存储和在线服务。首先进行医学影像数据库建设的需求分析和数据资源调查,围绕临床研究主题需求设计医学影像数据库的系统结构。然后,应用"数据库—样本数据—影像文件"三级信息组织模型、基于DICOM标准的医学影像数据处理、"数据库索引+Zip文件"的影像文件管理与缓存机制等技术实现该系统。系统支持DICOM、JPG等多种图像格式和组合查询模式,测试运行取得良好效果。     

医学超声图像分析的研究进展

超声成像是四大医学影像技术之一，由于其特有的实时性、无损性、廉价性被广泛应用于医疗和诊断，因此，有必要对医学超声图像的计算机分析进行研究。从图像分割、图像配准及组织定征和生物测量三个医学超声图像分析的主要方面对国内外近年来的主要研究情况进行综述和评价，并在此基础上探讨其发展前景。     

基于小波分析的医学图像融合技术及其效果评价

多模医学图像融合技术是近年兴起的一种新技术，在医学影像技术学和放射医学领域中有极为重要的应用价值。本文中我们使用小波分析算法有效的实现了基于像素级的多重图像融合，并给出了量化的评判指标。实验结果表明，基于小波分析的医学图像融合技术能有效的保留原始多源图像的边缘和纹理特征。避免融合图像出现平均化。     

应用MPEG-7建立乳腺X线影像数据库

乳腺肿瘤是妇女的多发疾病。建立有效的数字化乳腺X线影像存储与检索技术，可以充分利用医疗资源，并且帮助用户进行个人健康管理。MPEG-7技术可以实现对多媒体内容低级特征和高级语义信息的注释。将MPEG-7技术引入数字化乳腺X线影像存储，详细分析对医学影像MPEG-7注释以及将MPEG-7文件与医学图像一起存储到数据库的技术实现，在Linux系统下构建包含MPEG-7信息的数字化乳腺X线影像MySQL数据库和基于网络的查询系统。结果说明使用MPEG-7对医学图像低级特征和高级语义注释是可行的，数据库中存储的注释文件有利于医学图像高级语义信息的检索。     

PACS就绪 网络先行

网络和影像处理科技的快速发展，带动了医学影像技术的普及和应用。医疗图像存档与通信系统(Picture Archiving and Communications System，PACS)就是计算机网络技术与影像处理技术在临床医学中高度融合的产物，它将医学影像资料转化为计算机能够识别的数字信息，     

基于医学影像计算机辅助诊断的分割方法

本文在综合介绍目前基于医学影像的计算机辅助诊断(MICAD)研究工作的基础上，重点分析了MICAD主要使用的图像分析和处理技术。作为例子重点介绍了MICAD对图像分割的要求，介绍了目前我们正在开展的最小近邻算法(KNN)和模糊最小紧邻算法(FKNN)进行图像分割的工作，并提出了如何用相邻像素的信息，进一步提高分割的准确性的思路，为后面的计算机自动识别提供依据。而计算机自动识别是基于医学影像的计算机辅助诊断过程自动化的基础。     

基于JPEG技术的CT图像压缩方法的研究

CT图像在医学影像诊断中占有重要地位，CT图像压缩技术是PACS系统的重要组成部分。JPEG静止图像压缩标准目前已成为一种广泛应用的图像压缩技术。JPEG充分利用人眼的视觉特性，对DCT系数的低频系数进行细量化，而对高频系数进行粗量化，但未对图像的边缘特征进行特殊的处理。而图像的部分边缘特征又正是隐含于DCT高频系数中。文中从图像边缘信息的谱分析入手，通过理论推导及实例分析得到平直单边缘图像子块其DCT系数能量的分布规律，并以此为理论基础设计出JPEG中DCT系数量化表(Q表)，实验结果表明该Q表对非平直边缘图象子块没有影响，而对含有平直边缘图像子块的边缘信息进行了有效的保持。     

基于内容检索的(医学)图像数据库研究

通过对目前提出的各种实现基于图像内容查询的方法的分析和比较，结合最新的数据库应用系统构建技术，寻找一种可行的，支持图像内容查询的实用图像数据库应用系统的构建方法。     

图像储存和传递系统与远程放射学

图像储存和传递系统（ＰＡＣＳ）与远程放射学是在计算技术与微电子技术迅速发展的基础上，随着各种医学影像设备的日益广泛应用而建立起来的一门新兴学科。本文简述了ＰＡＣＳ的形成背景，该系统建立的可能性与其基本组成，以及可望取得的一些明显效果；指出远程放对学的主要特点及在我国发展远程放射学的现实意义；最后介绍了关于图像综合诊断学的概念。     

数字图像中血管的分割与特征提取

目前,影像学手段已经成为医生诊断疾病的决定性依据,图像的数字化为医学影像的计算机处理和分析、进而辅助临床诊断提供了可能。文章综述了数字图像中血管图像的分割与特征提取的常用技术和方法及其在临床医学中的应用进展。     

Research and Realization of Medical Image Fusion Based on Three-Dimensional Reconstruction

A new medical image fusion technique is presented. The method is based on three-dimensional reconstruction. After reconstruction, the three-dimensional volume data is normalized by three-dimensional coordinate conversion in the same way and intercepted through setting up cutting plane including anatomical structure,as a result two images in entire registration on space and geometry are obtained and the images are fused at last. Compared with traditional two-dimensional fusion technique,three-dimensional fusion technique can not only resolve the different problems existed in the two kinds of images,but also avoid the registration error of the two kinds of images when they have different scan and imaging parameter. The research proves this fusion technique is more exact and has no registration, so it is more adapt to arbitrary medical image fusion with different equipments.     

Watermark Compression in Medical Image Watermarking Using Lempel-Ziv-Welch (LZW) Lossless Compression Technique

In teleradiology, image contents may be altered due to noisy communication channels and hacker manipulation. Medical image data is very sensitive and can not tolerate any illegal change. Illegally changed image-based analysis could result in wrong medical decision. Digital watermarking technique can be used to authenticate images and detect as well as recover illegal changes made to teleradiology images. Watermarking of medical images with heavy payload watermarks causes image perceptual degradation. The image perceptual degradation directly affects medical diagnosis. To maintain the image perceptual and diagnostic qualities standard during watermarking, the watermark should be lossless compressed. This paper focuses on watermarking of ultrasound medical images with Lempel-Ziv-Welch (LZW) lossless-compressed watermarks. The watermark lossless compression reduces watermark payload without data loss. In this research work, watermark is the combination of defined region of interest (ROI) and image watermarking secret key. The performance of the LZW compression technique was compared with other conventional compression methods based on compression ratio. LZW was found better and used for watermark lossless compression in ultrasound medical images watermarking. Tabulated results show the watermark bits reduction, image watermarking with effective tamper detection and lossless recovery.     

一个基于内容检索的医学图像数据库

介绍了一个基于图像内容检索的医学图像数据库系统。分别讨论了用于图像内容检索的颜色、纹理和形状特征以及在此特征集下的图像相似性度量 ;介绍了数据库的组织及该系统的界面     

A Mammography Database and View System for African-American Patients

We have digitized mammography films of African-American patients treated in the Howard University Hospital Radiology Department and have developed a database using these images. Two hundred and sixty cases totaling more than 5,000 images have been scanned with a high resolution Kodak LS85 laser scanner. The database system and web-based search engine were developed using MySQL and PHP. The database has been evaluated by medical professionals, and the experimental results obtained so far are promising with high image quality and fast access time. We have also developed an image viewing system, D-Viewer, to display these digitized mammograms. This viewer is coded in Microsoft Visual C# and is intended to help medical professionals view and retrieve large data sets in near real time. Finally, we are currently developing an image content-based retrieval function for the database system to provide improved search capability for the medical professionals.     

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。     

A Blurring Index for Medical Images

This study was undertaken to investigate a useful image blurring index. This work is based on our previously developed method, the Moran peak ratio. Medical images are often deteriorated by noise or blurring. Image processing techniques are used to eliminate these two factors. The denoising process may improve image visibility with a trade-off of edge blurring and may introduce undesirable effects in an image. These effects also exist in images reconstructed using the lossy image compression technique. Blurring and degradation in image quality increases with an increase in the lossy image compression ratio. Objective image quality metrics [e.g., normalized mean square error (NMSE)] currently do not provide spatial information about image blurring. In this article, the Moran peak ratio is proposed for quantitative measurement of blurring in medical images. We show that the quantity of image blurring is dependent upon the ratio between the processed peak of Moran's Z histogram and the original image. The peak ratio of Moran's Z histogram can be used to quantify the degree of image blurring. This method produces better results than the standard gray level distribution deviation. The proposed method can also be used to discern blurriness in an image using different image compression algorithms.     

Improving knowledge management through the support of image examination and data annotation using DICOM structured reporting

An important effort has been invested on improving the image diagnosis process in different medical areas using information technologies. The field of medical imaging involves two main data types: medical imaging and reports. Developments based on the DICOM standard have demonstrated to be a convenient and widespread solution among the medical community. The main objective of this work is to design a Web application prototype that will be able to improve diagnosis and follow-on of breast cancer patients. It is based on TRENCADIS middleware, which provides a knowledge-oriented storage model composed by federated repositories of DICOM image studies and DICOM-SR medical reports. The full structure and contents of the diagnosis reports are used as metadata for indexing images. The TRENCADIS infrastructure takes full advantage of Grid technologies by deploying multi-resource grid services that enable multiple views (reports schemes) of the knowledge database. The paper presents a real deployment of such Web application prototype in the Dr. Peset Hospital providing radiologists with a tool to create, store and search diagnostic reports based on breast cancer explorations (mammography, magnetic resonance, ultrasound, pre-surgery biopsy and post-surgery biopsy), improving support for diagnostics decisions. A technical details for use cases (outlining enhanced multi-resource grid services communication and processing steps) and interactions between actors and the deployed prototype are described. As a result, information is more structured, the logic is clearer, network messages have been reduced and, in general, the system is more resistant to failures.     

医学图像处理中有关图像分割的新技术

图像分割是图像处理中最基本和最主要的技术.本文简要介绍了医学图像分割的常用分割方法,主要包括阈值分割、神经网络分割、模糊分割、遗传算法、统计方法和基于特定模型等方法的图像分割.并对其近年来的进展和应用进行了综述.     

M3D:面向3D打印的医学图像重建平台

本研究旨在构建面向3D打印的医学图像3D重建平台,实现医学影像数据的目标分割、3D重建与3D打印所需区域裁剪与输出功能。该软件平台采用Qt设计用户界面,调用ITK、VTK类库处理医学影像数据。软件平台实现了医学影像数据的输入输出及处理、分割与3D重建等功能;在3D打印模型输出前,可实现对感兴趣区域的截取。以肘关节为例,利用该平台可实现模型重建,截取区域输出STL文件并完成3D打印。结果表明,该软件平台操作简单、界面简洁,可以从医学影像数据中重建得到3D模型,并进行3D打印,具有重要的临床应用价值。