PACS与DICOM

近几年来随着医院信息化的深入发展及数字影像时代的到来，医学图像归档和通讯系统（picture archiving and communication system，PACS）在我国已开始逐渐发展起来。不少PACS软件产品都称是依据医学数字成像和交换（digital imaging and communication in medicine，DICOM）标准^[1]开发并与DICOM兼容的。但是对PACS、DICOM的理解及PACS究竟如何遵从DICOM标准都是一个值得深入探讨的问题。     

有关PACS构建的几点讨论

1　前言医学图像归档和通讯系统 (ｐｉｃｔｕｒｅａｒｃｈｉｖｉｎｇａｎｄｃｏｍｍｕｎｉｃａｔｉｏｎｓｙｓｔｅｍ ,ＰＡＣＳ)的构建是目前各大医院网络化的热门话题 ,目前情况下 ,ＰＡＣＳ是否尽快上马 ,上什么类型的ＰＡＣＳ (Ｍｉｎｉ -ＰＡＣＳ ,Ｌｏｃａｌ -ＰＡＣＳ或全院性的大型ＰＡＣＳ) ,采取什么方式进行ＰＡＣＳ建设及ＰＡＣＳ与ＨＩＳ合成等等 ,都是有关ＰＡＣＳ建设需要考虑的关键问题。本文结合我院ＰＡＣＳ系统论证及初步构建方案的设想 ,讨论有关ＰＡＣＳ构建初期所面临的几个关键问题。2　ＰＡＣＳ的历史与目前我国ＰＡ…     

PACS系统影像存储解决方案

医学图像存档与传输系统(PACS)是目前数字化医院建设的重点和难点,PACS系统需要一个高性能的影像存储系统支撑.本文分析了PACS系统影像存储的特点,介绍了分级存储机制实现对医学影像的存储管理,并比较了三种在线存储设备解决方案的优点和缺点.     

图像归档和通讯系统（PACS）的发展与应用

图像归档和通讯系统，是经通讯网络获取、存储、管理和显示放射医学图像的集成信息系统。近年来，国外的ＰＡＣＳ技术和应用已逐步进入成熟期，有大量的研究成果和应用实例；但我国的ＰＡＣＳ研究和应用因起步较晚，尚处在相对落后的局面。本介绍了ＰＡＣＳ系统发展历程，概述了国外ＰＡＣＳ研究和应用的现状，最后分析了国内ＰＡＣＳ的发展状况，展望了其在我国医疗信息系统发展中的应用前景。     

子宫内膜异位症的MRI影像病理学研究

目的 分析子宫内膜异位症的磁共振（MRI）影像特征。材料与方法 回顾性分析51例子宫内膜异位症的MRI影像特征，全部病例经手术及病理证实。结果 子宫增大48例；T2WI及T1WI显示子宫有弥散分布的片状低信号区内夹杂斑点状高信号30例；T2WI显示子宫低信号区内夹杂斑点状高信号，T1WI呈低信号21例，29个卵巢囊肿，T1WI及T2WI均呈高信号有15个，T1WI呈高信号而T2WI呈低或等信号5个，T1WI和T2WI均呈混杂信号9个。结论 子宫内膜异位症的主要MRI表现：（1）子宫内出现片状低信号区，同时夹杂斑点状高信号；（2）卵巢巧克力囊肿在T1WI和T2WI均为高信号或以高信号为主的混杂信号。     

肘关节副韧带的MRI检查方法及影像特点

目的：研究肘关节有关结构的MRI检查方法和影像特点。方法：急性肘关节后脱位2例和慢性肘关节后脱位1例，行MRI检查。结果：冠状位MRI可清楚地显示肘关节诸结构，并可显示损伤的肝关节副韧带，矢状位部分层面可分别显示尺侧和桡侧副韧带，横断面不能完整地显示肘关节副韧带。副韧带损伤的常规MRI影像特点，在冠状位SE序列T2加权像，呈低信号，尺侧副韧带在尺骨冠突内侧呈薄止点，线型或稍呈弧形向近端，在肱骨骨侧髁止点稍扩散，其损伤的表现有韧带的增厚或变薄、韧带松驰及不连续包绕韧带的水肿或血肿的高信号影等。结论：肘关节副韧带的MRI检查是较准确、敏感、无损伤的方法，值得进行进一步探讨。     

图像归档和通讯系统(PACS)的发展与应用

图像归档和通讯系统 (Picture Archiving and Communication System,PACS) ,是经通讯网络获取、存储、管理和显示放射医学图像的集成信息系统。近年来 ,国外的 PACS技术和应用已逐步进入成熟期 ,有大量的研究成果和应用实例 ;但我国的 PACS研究和应用因起步较晚 ,尚处在相对落后的局面。本文介绍了 PACS系统发展历程 ,概述了国外 PACS研究和应用的现状 ,最后分析了国内 PACS的发展状况 ,展望了其在我国医疗信息系统发展中的应用前景。     

基于PACS的彩超影像采集工作站的设计与应用

为了使医院模拟彩超诊断仪能够接入现有PACS系统,促进医院数字化与信息化发展,本文介绍了一种基于PACS系统的彩超影像采集工作站的设计方法及其应用.该系统使彩超诊断仪与PACS系统得以紧密地联系起来,实现了彩超图像的采集,同时按照DIC0M标准实现了彩超图像的存储与传输等一系列功能,推动了PACS系统的发展和医院信息系统的完善.     

医院PACS的引进与评价

本文对医学影像归档与传输系统(PACS)引进的必要性、引进方式与规模进行了阐述，重点对PACS产品的供应商、服务商和产品本身的性能进行了系统全面的评价，对医院引进PACS的论证有比较大的指导意义。     

PACS系统在HS网上的实现

主要介绍了在ＨＩＳ网上开发的“医学影像资源共享系统”,该系统主要功能是在ＨＩＳ网上实现了ＰＡＣＳ系统功能。     

Magnetic Resonance (MR) Metabolic Imaging in Glioma

This review is focused on describing the use of magnetic resonance (MR) spectroscopy for metabolic imaging of brain tumors. We will first review the MR metabolic imaging findings generated from preclinical models, focusing primarily on in vivo studies, and will then describe the use of metabolic imaging in the clinical setting. We will address relatively well‐established ¹H MRS approaches, as well as ³¹P MRS, ¹³C MRS and emerging hyperpolarized ¹³C MRS methodologies, and will describe the use of metabolic imaging for understanding the basic biology of glioma as well as for improving the characterization and monitoring of brain tumors in the clinic.     

PACS诊断工作站匹配小型DSA在介入治疗中的应用

目的 探讨PACS诊断工作站与小型DSA匹配在介入治疗中的应用价值。方法 PACS诊断工作站通过视频采集一转换方式采集岛津公司的WHA-50N／S小型DSA的PH-DSA方式获得的视频图像，使用DIGOM 3．0国际标准。对采用该系统检查治疗的67例图像资料进行分析，评价该工作站的使用效能。结果 将PACS诊断工作站与小型DSA相接后，将原来的PH-DSA视频图像转变为10～25帧／S的数字DSA图像，可上传输至PACS，达到资料共享。提高了图像后处理的功能。应用该系统获得的数字图像能够保持原设备的清晰程度，无明显失真，可以显示1～2mm的3～4级血管。结论采用小型DSA与PACS诊断工作站相匹配，可以为介入治疗的开展提供可靠的保障。     

Histogram Analysis of Hepatobiliary Phase MR Imaging as a Quantitative Value for Liver Cirrhosis: Preliminary Observations

Purpose

To investigate whether histogram analysis of the hepatobiliary phase on gadoxetate enhanced-MRI could be used as a quantitative index for determination of liver cirrhosis.

Materials and Methods

A total of 63 patients [26 in a normal liver function (NLF) group and 37 in a cirrhotic group] underwent gadoxetate-enhanced MRI, and hepatobiliary phase images were obtained at 20 minutes after contrast injection. The signal intensity of the hepatic parenchyma was measured at four different regions of interest (ROI) of the liver, avoiding vessels and bile ducts. Standard deviation (SD), coefficient of variation (CV), and corrected CV were calculated on the histograms at the ROIs. The distributions of CVs calculated from the ROI histogram were examined and statistical analysis was carried out.

Results

The CV value was 0.041±0.009 (mean CV±SD) in the NLF group, while that of cirrhotic group was 0.071±0.020. There were statistically significant differences in the CVs and corrected CV values between the NLF and cirrhotic groups (p<0.001). The most accurate cut-off value among CVs for distinguishing normal from cirrhotic group was 0.052 (sensitivity 83.8% and specificity 88.5%). There was no statistically significant differences in SD between NLF and cirrhotic groups (p=0.307).

Conclusion

The CV of histograms of the hepatobiliary phase on gadoxetate-enhanced MRI may be useful as a quantitative value for determining the presence of liver cirrhosis.     

Combination of feature-reduced MR spectroscopic and MR imaging data for improved brain tumor classification

The purpose of this paper is to evaluate the effect of the combination of magnetic resonance spectroscopic imaging (MRSI) data and magnetic resonance imaging (MRI) data on the classification result of four brain tumor classes. Suppressed and unsuppressed short echo time MRSI and MRI were performed on 24 patients with a brain tumor and four volunteers. Four different feature reduction procedures were applied to the MRSI data: simple quantitation, principal component analysis, independent component analysis and LCModel. Water intensities were calculated from the unsuppressed MRSI data. Features were extracted from the MR images which were acquired with four different contrasts to comply with the spatial resolution of the MRSI. Evaluation was performed by investigating different combinations of the MRSI features, the MRI features and the water intensities. For each data set, the isolation in feature space of the tumor classes, healthy brain tissue and cerebrospinal fluid was calculated and visualized. A test set was used to calculate classification results for each data set. Finally, the effect of the selected feature reduction procedures on the MRSI data was investigated to ascertain whether it was more important than the addition of MRI information. Conclusions are that the combination of features from MRSI data and MRI data improves the classification result considerably when compared with features obtained from MRSI data alone. This effect is larger than the effect of specific feature reduction procedures on the MRSI data. The addition of water intensities to the data set also increases the classification result, although not significantly. We show that the combination of data from different MR investigations can be very important for brain tumor classification, particularly if a large number of tumors are to be classified simultaneously.     

应用层次分析法和德尔菲法构建医学图像存档与传输系统评估指标体系

目的 应用层次分析法（AHP）和德尔菲法建立医学图像存档与传输系统（PACS）评估指标体系。方法 回溯性检索2003年 ～ 2012年PubMed、Embase、Science Citation Index、Cochrane Library、万方数据、中国知网等6种电子数据库的PACS文献,在文献分析的基础上,邀请医学影像、计算机应用、生物医学工程、PACS项目管理、临床医疗等专业的9名专家咨询,采用德尔菲法建立评估体系的指标框架,采用AHP确定评估体系各级指标权重,并计算下级指标相对于上级指标的组合权重。结果 构建的评估体系包括一级指标5个、二级指标23个。5个一级指标供应商综合能力、产品成熟性与先进性、系统安全性与可靠性、系统准确性和系统性能的权重分别为0.091 7、0.224 7、0.232 6、0.181 0、0.270 0;各级指标权重均满足一致性检验,所得权重是可以接受的;二级指标组合权重按权重大小排序,权重最大的前5位分别是“工作站性能”、“系统存储与影像存档性能”、“影像质量及显示性能”、“数据的完整性”和“数据安全策略”。结论 德尔菲法和APH相结合是建立评估体系的有效方法,同时,这种构建评估体系的方法也为大型设备的招标评估指标的制定提供新思路。     

恶性蝾螈瘤MR影像分析（附1例报道）

目的：探讨恶性蝾螈瘤（MTT）的MRI表现和临床病理特点,提高临床对MTT的认识.方法：手术切除辅以放疗治疗右前臂MTT 1例.结合文献复习,分析MTT的MRI表现及病理特征.结果：MTT的MRI表现为T1WI稍低信号、T2WI高信号的软组织肿块,肿瘤信号不均、T2WI上高信号肿块影内环形或线样低信号分隔影或许是MTT的特征性MRI表现之一.MTT的恶性度高,其治疗以手术切除为主,疗效及预后不佳,易在短期内复发及转移.结论：深入了解MTT的MRI表现,对MTT的早期诊断、早期治疗具有重要价值.     

基于MR分子成像的分子探针及其研究进展

MR分子成像可以利用MRI技术并借助对比剂的生化特征来直接或间接地反映目的基因的情况,其核心任务的关键在于分子探针的选用。本文介绍了分子探针在MRI技术中的重要性及MR分子成像对分子探针的要求,且着重阐述了MR分子成像中分子探针的种类及其应用进展情况。     

Integration of Temporal Subtraction and Nodule Detection System for Digital Chest Radiographs into Picture Archiving and Communication System (PACS): Four-year Experience

Since May 2002, temporal subtraction and nodule detection systems for digital chest radiographs have been integrated into our hospital’s picture archiving and communication systems (PACS). Image data of digital chest radiographs were stored in PACS with the digital image and communication in medicine (DICOM) protocol. Temporal subtraction and nodule detection images were produced automatically in an exclusive server and delivered with current and previous images to the work stations. The problems that we faced and the solutions that we arrived at were analyzed. We encountered four major problems. The first problem, as a result of the storage of the original images’ data with the upside-down, reverse, or lying-down positioning on portable chest radiographs, was solved by postponing the original data storage for 30 min. The second problem, the variable matrix sizes of chest radiographs obtained with flat-panel detectors (FPDs), was solved by improving the computer algorithm to produce consistent temporal subtraction images. The third problem, the production of temporal subtraction images of low quality, could not be solved fundamentally when the original images were obtained with different modalities. The fourth problem, an excessive false-positive rate on the nodule detection system, was solved by adjusting this system to chest radiographs obtained in our hospital. Integration of the temporal subtraction and nodule detection system into our hospital’s PACS was customized successfully; this experience may be helpful to other hospitals.     

Polymers as Probes for Multimodal Imaging with MRI

Multimodal imaging agents provide unique opportunities to probe disease states in vivo. The development of polymeric molecular imaging agents that combine the high‐resolution capabilities of MRI with other more sensitive techniques leads to significant possibilities for increasing our understanding of biological processes in live animals. To fully utilise this capability, advanced architectural polymers are being developed in which the material properties of the multimodal imaging agent are underpinned by a strong understanding of the underlying synthetic and physical chemistry of the macromolecules. In this report, the development of new polymers as multimodal imaging agents utilising MRI for preclinical in vivo studies is described.