基于阵列式换能器的光声成像系统的实现

目的:本文设计了一套光声成像(photoacoustic imaging,PAI)系统,由脉冲激光、阵列换能器、临床超声(ultrasound,US)主机、软件平台以及成像样品组成。系统的图像质量、最大成像深度等重要参数需通过实验进行确定。方法:使用本系统对黑色头发丝横截面进行成像,比较、分析光声(photoacoustic,PA)信号幅值的半极大处全宽度以量化图像分辨率。此外,使用系统对特定的光吸收体和鸡胸肉组织进行成像,确定系统的成像深度。结果:实验结果证明了PAI系统的实现,其PA图像的平均轴向和横向分辨率分别约为0.18 mm和1.44mm,系统的最大成像深度达到4.6 cm。结论:本PAI系统PA图像分辨率优于US主机获得的US图像分辨率,系统最大成像深度与其他国际研究组的系统成像深度的数量级一致。通过进一步优化与活体组织实验的开展,本PAI系统将有望实现临床成像诊断。     

计算机视觉技术在昆虫识别中的应用进展

介绍计算机视觉技术的定义,组成系统和发展状况,总结其在昆虫识别中的应用,指出目前存在的问题以及需要重点解决的关键技术．为今后的深入研究提出了一些建议和方向。     

光子计数方法探测明亮杆菌的发光图像

本文研制了用生物倒置显微镜和以微通道板为核心的超高灵敏度光电成像系统组成的光子计数显微成像系统,此系统具有高空间放大倍数（１６０×）和极高的光子放大倍数（１０７）,可探测到大小为μｍ量级,发光强度为１００光子／秒的发光图像。应用此系统拍摄到了单个明亮发光杆菌（Ｐｈｏｔｏｂａｃｔｅｒｉｕｍｐｈｏｓｐｈｏｒｅｕｍ）的发光图像,图像显示明亮发光杆菌的大小为２．４×０．６０（μｍ）２,单个细菌的发光强度在１００光子／秒量级。上述实验为明亮杆菌在环境保护中的应用提供了基本参数,也为进一步从细胞水平上研究发光细菌提供了可能。     

自发和光诱导的生物超微弱发光图像的观测

本文报导一种最新研制的高探测灵敏度,低噪声的光子图像观测系统。利用该系统观测了绿豆芽,小葱和树叶等活体品的超弱发光图像。     

共聚焦图像数据的三维重建和显示

本文介绍利用激光扫描共聚焦显微镜获得的共聚焦图像的三维重建和显示方法,并以ＡＣＡＳ Ｕｌｔｉｎａ３１２激光扫描共聚焦显微镜系统为例,分析了ＳＰＦ算法、投影算法和深度阴影算法等共聚焦图像数据的三维重建和图像显示方法的特点。     

基于图像处理的树叶面积测量系统

以数字图像处理技术为基础,对数码相机拍摄的含有参照硬板和树叶的照片进行图像分析处理,提出了获取树叶的实际面积测量系统的一种独特实现方案。采用此方案开发出相应的应用软件,应用于树叶面积的测量计算,获得十分满意的结果。     

自然图像效率编码

效率编码理论认为经过漫长历史进化,大脑感知系统有效地适应了自然环境.自然图像统计规律计算建模对视觉信息处理机理的理解大有裨益.本文简要回顾近期视觉系统对自然图像效率编码的最新进展.     

视频图象存储仪

本文介绍一种与影象增强X线电视系统配用的视频图象存储仪,1M字节的动态RAM存储体,可存储4帧分辨率为512×512的黑白图象,精度8位,256灰阶。在输入有效视频信号幅度变化大于25dB的范围内,均能得到清晰的实时或冻结图象。该存储仪亦可用于其他应用电视系统。     

三维胎儿图像系统

日前,日本东京大学开发了可以实时显示三维胎儿图像系统,可用于对患病胎儿进行治疗。所谓胎儿治疗是指胎儿还在子宫内时,就对先天性横膈膜疝气等疾病进行治疗。比起出生后的手术治疗,胎儿治疗效果更好。如果手术中能够借助三维图像进行观察,就可以正确把握手术器具与胎儿的距离,大大提高安全性和准确性。     

医学图像融合技术的研究

利用图像融合技术,将不同模态的医学图像有机地结合在一起,可以充分利用各种医学图像的优点,为临床诊断和治疗提供帮助。本文主要介绍了医学图像融合技术的基本概念、发展情况、常用方法及面临的困难等,并对医学图像的研究前景作了预测。     

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。     

Overview of capacity data

This paper presents an overview of the data from 15 cases collected with the CAPACITY software for cost analysis of PACS. The data suggest that both hospital wide and partial PACS implementations do not pay back yet. Only Nuclear Medicine PACS systems may be introduced cost-neutral in the near future. Because of the assumed price drop of hardware components of 5–25% per year, hospital wide and partial PACS may allow cost savings within the next 10–20 years. There are major differences in viewpoints concerning the required PACS configurations and their costs. The experiences with the CAPACITY software suggest the need for the establishment of key rules, for designing a PACS configuration and for estimating PACS costs.     

PACS辅助教学在医学影像学实习教学中的应用探讨

尝试应用影像存储及传输系统(Picture Archiving and Communication System,PACS),对我院临床本科生进行影像学实习教学。首先应用PACS建立电子影像学图片库,学生在PACS联网的计算机上学习教学内容,通过定期随堂测验、期末考试和课后问卷调查评估PACS辅助教学的教学效果,对PACS辅助教学在医学影像学实习教学中的应用价值进行探讨。与以往传统医学影像学实习教学方法相比,PACS辅助教学在医学影像学实习教学中具有激发学生学习主动性、提高学习效率和学生读片能力的优越性,显著提高教学效果和教学质量,对促进医学影像学教学改革具有重要意义。     

PACS的高级预防维护技术

目的 通过讨论PACS高级预防维护技术,供同他人在日常维护过程中有一定地借鉴作用.方法 从PACS数据库性能检测与优化,存储设备检测及PACS各应用软件模块三方面进行阐述.结果 经过医院一线安装维护人员和PACS厂家多年实践的总结,拥有一定的可参考依据.结论 PACS的高级预防维护是一个复杂的系统工程,包括一般维护和高级维护在内的实践理论才刚刚起步,科学的、规范化的预防维护需要不断地完善和发展.     

The impact of PACS on research and education

Picture Archiving and Communication Systems (PACS) are rapidly evolving and the total digital radiology department may be a reality within the next decade. PACS can have a major impact on the educational and research responsibilities of a medical institution. The possibility of correlating real patient data with existing radiological teaching files opens up numerous possibilities. Multi-institutional research can be strengthened by employing the PACS as the means to the end. This paper discusses the representative examples of how teaching and research can be enhanced with PACS and the technical requirements to achieve the inter-connectivity.     

Evaluation of PACS-induced organizational change

Filmless digital imaging with a PACS will affect health care institutions by changing the handling of clinically relevant information, altering needed staffing levels, and possibly affecting both the quality and cost of care. Economic evaluation of PACS compares the costs and/or benefits of PACS with those of all other relevant alternatives. Other evaluations may focus on narrower research questions. This paper discusses methodological considerations in economic evaluation, methods of time measurement, and the methods and results of several applied assessments of PACS effects on the medical imaging department or the hospital.     

PACS在口腔根管治疗中的应用

医学影像存储与传输系统（PACS）的建设改变了原有的摄片和看片模式,对提高医院的医疗质量的到了很大的推进作用。该文论述了我院PACS系统的特点以及在口腔根管治疗中的应用。并与原来的胶片流程做了对比,研究了PACS系统在根管治疗中的应用的优势以及今后的发展前景。     

Current views on the functionalities of PACS

The concept of PACS has evolved from a central storage of medical images to a distributed data and image management system. The trend and evolution of the definition and design of PACS systems is described in this paper. Special emphasis on the concept of distributed and open architecture is given with a discussion of the advantages and disadvantages of each approach. A hospital-wide PACS system designed based on a distributed architecture integrated with a Hospital Information System (HIS) at the University Hospital of Geneva is further described.     

Workshop aims,outline of the program

This workshop on the Technology Assessment of PACS has been organized as a rounding off of the Technology Assessment Activities which were initiated within the Dutch PACS Project (1986–1989). It is made possible by a funding from the Dutch Ministry of Health Care (WVC). We hope it will be not only a rounding off, but will contribute to more intensive cooperations in this area. In the scope of the Dutch PACS project, the software package CAPACITY for cost analyses of PACS has been developed, to stimulate the dialogue and exchange of data. During the workshop, the data which were collected with CAPACITY are used as a framework for discussions. This paper presents the outline of the workshop, its background, its aims and the program.     

SORLA-Dependent and -Independent Functions for PACS1 in Control of Amyloidogenic Processes

Sorting-related receptor with A-type repeats (SORLA) is a sorting receptor for the amyloid precursor protein (APP) that prevents breakdown of APP into Aβ peptides, a hallmark of Alzheimer''s disease (AD). Several cytosolic adaptors have been shown to interact with the cytoplasmic domain of SORLA, thereby controlling intracellular routing of SORLA/APP complexes in cell lines. However, the relevance of adaptor-mediated sorting of SORLA for amyloidogenic processes in vivo remained unexplored. We focused on the interaction of SORLA with phosphofurin acidic cluster sorting protein 1 (PACS1), an adaptor that shuttles proteins between the trans-Golgi network (TGN) and endosomes. By studying PACS1 knockdown in neuronal cell lines and investigating transgenic mice expressing a PACS1-binding-defective mutant form of SORLA, we found that disruption of SORLA and PACS1 interaction results in the inability of SORLA/APP complexes to sort to the TGN in neurons and in increased APP processing in the brain. Loss of PACS1 also impairs the proper expression of the cation-independent mannose 6-phosphate receptor and its target cathepsin B, a protease that breaks down Aβ. Thus, our data identified the importance of PACS1-dependent protein sorting for amyloidogenic-burden control via both SORLA-dependent and SORLA-independent mechanisms.