Development of a Next-Generation Automated DICOM Processing System in a PACS-Less Research Environment

The use of clinical imaging modalities within the pharmaceutical research space provides value and challenges. Typical clinical settings will utilize a Picture Archive and Communication System (PACS) to transmit and manage Digital Imaging and Communications in Medicine (DICOM) images generated by clinical imaging systems. However, a PACS is complex and provides many features that are not required within a research setting, making it difficult to generate a business case and determine the return on investment. We have developed a next-generation DICOM processing system using open-source software, commodity server hardware such as Apple Xserve®, high-performance network-attached storage (NAS), and in-house-developed preprocessing programs. DICOM-transmitted files are arranged in a flat file folder hierarchy easily accessible via our downstream analysis tools and a standard file browser. This next-generation system had a minimal construction cost due to the reuse of all the components from our first-generation system with the addition of a second server for a few thousand dollars. Performance metrics were gathered and the system was found to be highly scalable, performed significantly better than the first-generation system, is modular, has satisfactory image integrity, and is easier to maintain than the first-generation system. The resulting system is also portable across platforms and utilizes minimal hardware resources, allowing for easier upgrades and migration to smaller form factors at the hardware end-of-life. This system has been in production successfully for 8 months and services five clinical instruments and three pre-clinical instruments. This system has provided us with the necessary DICOM C-Store functionality, eliminating the need for a clinical PACS for day-to-day image processing.     

A DICOM document-oriented approach to PACS infrastructure

The need for long-term storage requires the future migration of image data from a PACS to its successor system. This paper considers the cost of such migration. It is proposed that storage of data as “documents” in DICOM Part 10 formats on industrystandard media could reduce the time and cost of data migration relative to on-line DICOM transfer. The relation to present efforts in developing document-oriented electronic patient records is discussed. DICOM Part 10 files are found to be a sufficient representation of image documents, but additional software tools will be needed to reach its full potential. There is a significant cost benefit of the document storage method, but it is one of many factors which must be balanced in the selection of a PACS.     

MyCases—A Portable Application for Radiologic Case Collections

Radiologists come across interesting patient cases almost every day. This work proposes a novel case database server for quick and easy storage of such cases including whole image series, patient data, and annotations. Cases can be added to the database by saving DICOM images into a predefined directory on the local network. The application automatically extracts patient and study data from the DICOM header and saves it in the database while images are stored as anonymized JPEG files. Users can mark their cases as private or public (visible to all users). Different data fields for annotations and categorization of a case are available. The user frontend also provides several retrieval mechanisms allowing for browsing the cases and performing different kinds of search queries. The stored series can be scrolled interactively in the form of scrollable image stacks. The project is realized as a web-based application using a portable web and database server software package (XAMPP). This makes the system very lightweight and easy to run on almost any desktop computer, even from a USB flash drive, without the need for deeper IT knowledge and administrative rights.     

An Improved Tamper Detection and Localization Scheme for Volumetric DICOM Images

The development of teleradiology brings the convenience of global medical record access along with the concerns over the security of medical images transmitted over the open network. With the prevailing adoption of three-dimensional (3-D) imaging modalities, it is vital to develop a security mechanism to provide large volumes of medical images with privacy and reliability. This paper presents the development of a new and improved method of implementing tamper detection and localization based on a fully reversible digital watermarking scheme for the protection of volumetric DICOM images. This tamper detection and localization method utilizes the 3-D property of volumetric data to achieve much faster processing time at both sender and receiver sides without compromising tamper localization accuracy. The performance of the proposed scheme was evaluated by using sample volumetric DICOM images. Results show that the scheme achieved on average about 65 % and 72 % reduction in watermarking and dewatermarking processing time, respectively. For cases where the images had been tampered, it is possible to detect and localize the tampered areas with improved localization resolution in the images using the scheme.     

Development of Diagnostic Reference Levels Using a Real-Time Radiation Dose Monitoring System at a Cardiovascular Center in Korea

Digital cardiovascular angiography accounts for a major portion of the radiation dose among the examinations performed at cardiovascular centres. However, dose-related information is neither monitored nor recorded systemically. This report concerns the construction of a radiation dose monitoring system based on digital imaging and communications in medicine (DICOM) data and its use at the cardiovascular centre of the University Hospitals in Korea. The dose information was analysed according to DICOM standards for a series of procedures, and the formulation of diagnostic reference levels (DRLs) at our cardiovascular centre represents the first of its kind in Korea. We determined a dose area product (DAP) DRL for coronary angiography of 75.6 Gy cm² and a fluoroscopic time DRL of 318.0 s. The DAP DRL for percutaneous transluminal coronary intervention was 213.3 Gy cm², and the DRL for fluoroscopic time was 1207.5 s.     

一种符合医学数字影像与通讯标准的医学影像管理系统的设计

医学影像的存储与传输在数字化医疗快速发展的今天占据着非常重要的地位。为了实现医学数字影像与通讯（DICOM）医学影像在局域网上的传输和查询,本文设计了一个符合DICOM标准的医学影像管理系统。该系统能对DICOM格式文件进行解析,并在数据库中把DICOM影像文件与对应的病历信息进行关联存储,可以给医院影像科提供完全数字化的影像和数据。此研究工作不仅满足了医院影像中心对大量影像数据存储的需求,同时也促进了PACS系统的发展。     

基于DICOM标准的EECP血液动力学波形数据转换的研究

目的：将目前增强型体外反搏（EECP）设备采集到的二进制数据文件转换为DICOM血液动力学波形文件。方法：在深入研究DICOM信息模型、DICOM波形文件结构、数据元素结构、嵌套数据集结构、波形IOD模块结构等的基础上，利用Visual C＋＋．Net工具，运用C＋＋面向对象编程思想，把数据元素、嵌套数据集、波形IOD及其操作服务抽象成类，再分别读取二进制数据文件的相关信息赋给波形类对应的数据成员，最后调用有关成员函数将其存储为DICOM波形文件。结果：设计出了基于DICOM标准的EECP血液动力学波形数据转换的应用程序。结论：DICOM标准的不断应用将涵盖所有医学成像和信号类设备，EECP数据的DICOM标准化转换，为其共享和充分利用提供了重要前提。     

由DICOM医学图像文件获得设备无关位图的方法

目的:根据临床调查.DICOM3.0医学图像文件格式的解析及解决其显示问题是医学图像处理的基础,对医学影像技术的研究有重要意义.方法:首先针对DICOM3.0标准,系统分析了DICOM医学图像文件格式,主要阐述了文件信息头和数据元素的格式,提出了在Windows平台下利用线性调窗实现DICOM图像的DIB位图显示.结果:利用线性调窗成功实现了CT、MR图像的显示,同时针对默认状态下显示效果欠佳,采用手动调窗改善显示效果.结论:实验证明,该方法能较好地实现DICOM医学图像的显示,满足一定的临床需求,同时也为后续工作奠定基础.     

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。     

Validating DICOM Content in a Remote Storage Model

Verifying the integrity of DICOM files transmitted between separate archives (eg, storage service providers, network attached storage, or storage area networks) is of critical importance. The software application described in this article retrieves a specified number of DICOM studies from two different DICOM storage applications; the primary picture archiving and communication system (PACS) and an off-site long-term archive. The system includes a query/retrieve (Q/R) module, storage service class provider (SCP), a DICOM comparison module, and a graphical user interface. The system checks the two studies for DICOM 3.0 compliance and then verifies that the DICOM data elements and pixel data are identical. Discrepancies in the two data sets are recorded with the data elements (tag number, value representation, value length, and value field) and pixel data (pixel value and pixel location) in question. The system can be operated automatically, in batch mode, and manually to meet a wide variety of use cases. We ran this program on a 15% statistical sample of 50,000 studies (7500 studies examined). We found 2 pixel data mismatches (resolved on retransmission) and 831 header element mismatches. We subsequently ran the program against a smaller batch of 1000 studies, identifying no pixel data mismatches and 958 header element mismatches. Although we did not find significant issues in our limited study, given other incidents that we have experienced when moving images between systems, we conclude that it is vital to maintain an ongoing, automatic, systematic validation of DICOM transfers so as to be proactive in preventing possibly catastrophic data loss.     

Rifampin stability in 7H9 broth and Löwenstein-Jensen medium

The objectives of this study were to monitor the stability of rifampin (RIF) in Löwenstein-Jensen medium (L-J medium) and 7H9 broth, which are the media commonly used for drug susceptibility testing (DST) of Mycobacterium tuberculosis. Rifampin degradation in stock solution, 7H9 broth, and L-J medium and during the inspissation process for L-J medium preparation was serially monitored by high-performance liquid chromatography (HPLC). L-J medium-based DST was conducted to examine the effect of L-J medium storage on the DST outcome. The RIF stock solution was stable for at least 3 months when kept at either 4°C or −20°C; RIF in 7H9 broth and L-J medium was almost 50% decayed after 1 week of storage at 37°C, and rifampin could not be detected in 7H9 or L-J medium after 3 weeks or 6 weeks of storage at 37°C. Approximately half of the drug was decomposed after 4 months of storage at 4°C for both media, and after 6 months of storage at 4°C, RIF in L-J medium was undetectable, while 38% of RIF remained in 7H9 medium. Approximately 21, 24, 29, and 35% RIF degradations were detected when the L-J medium was coagulated at 75°C, 80°C, 85°C, and 90°C, respectively. The DST outcomes when using L-J medium stored for different periods of time were consistent with the RIF concentration monitoring data. Rifampin in stock solution is stable for at least 3 months at a reduced storage temperature. Media containing RIF should be prepared strictly according to validated standard operating procedures. RIF degradation is a possible reason for false resistance categorizations of M. tuberculosis isolates in the clinical laboratory.     

VirtualPACS—A Federating Gateway to Access Remote Image Data Resources over the Grid

Collaborations in biomedical research and clinical studies require that data, software, and computational resources be shared between geographically distant institutions. In radiology, there is a related issue of sharing remote DICOM data over the Internet. This paper focuses on the problem of federating multiple image data resources such that clients can interact with them as if they are stored in a centralized PACS. We present a toolkit, called VirtualPACS, to support this functionality. Using the toolkit, users can perform standard DICOM operations (query, retrieve, and submit) across distributed image databases. The key features of the toolkit are: (1) VirtualPACS makes it easy to use existing DICOM client applications for data access; (2) it can easily be incorporated into an imaging workflow as a DICOM source; (3) using VirtualPACS, heterogeneous collections of DICOM sources are exposed to clients through a uniform interface and common data model; and (4) DICOM image databases without DICOM messaging can be accessed.

Optimization of PACS Data Persistency Using Indexed Hierarchical Data

We present a new approach for the development of a data persistency layer for a Digital Imaging and Communications in Medicine (DICOM)-compliant Picture Archiving and Communications Systems employing a hierarchical database. Our approach makes use of the HDF5 hierarchical data storage standard for scientific data and overcomes limitations of hierarchical databases employing inverted indexing for secondary key management and for efficient and flexible access to data through secondary keys. This inverted indexing is achieved through a general purpose document indexing tool called Lucene. This approach was implemented and tested using real-world data against a traditional solution employing a relational database, in various store, search, and retrieval experiments performed repeatedly with different sizes of DICOM datasets. Results show that our approach outperforms the traditional solution on most of the situations, being more than 600 % faster in some cases.     

基于NT服务的DICOM服务器端软件的设计

本文详细介绍了Windows NT以及Windows 2000操作系统下NT系统服务的设计过程，以及医学影像系统中数字图像通讯协议(DICOM)，并以此为基础，介绍了DICOM服务器端软件的系统服务程序的设计流程，以实现DICOM协议中服务类提供方(SCP)的功能。     

UMMPerfusion: an Open Source Software Tool Towards Quantitative MRI Perfusion Analysis in Clinical Routine

To develop a generic Open Source MRI perfusion analysis tool for quantitative parameter mapping to be used in a clinical workflow and methods for quality management of perfusion data. We implemented a classic, pixel-by-pixel deconvolution approach to quantify T1-weighted contrast-enhanced dynamic MR imaging (DCE-MRI) perfusion data as an OsiriX plug-in. It features parallel computing capabilities and an automated reporting scheme for quality management. Furthermore, by our implementation design, it could be easily extendable to other perfusion algorithms. Obtained results are saved as DICOM objects and directly added to the patient study. The plug-in was evaluated on ten MR perfusion data sets of the prostate and a calibration data set by comparing obtained parametric maps (plasma flow, volume of distribution, and mean transit time) to a widely used reference implementation in IDL. For all data, parametric maps could be calculated and the plug-in worked correctly and stable. On average, a deviation of 0.032 ± 0.02 ml/100 ml/min for the plasma flow, 0.004 ± 0.0007 ml/100 ml for the volume of distribution, and 0.037 ± 0.03 s for the mean transit time between our implementation and a reference implementation was observed. By using computer hardware with eight CPU cores, calculation time could be reduced by a factor of 2.5. We developed successfully an Open Source OsiriX plug-in for T1-DCE-MRI perfusion analysis in a routine quality managed clinical environment. Using model-free deconvolution, it allows for perfusion analysis in various clinical applications. By our plug-in, information about measured physiological processes can be obtained and transferred into clinical practice.     

A JAVA-based DICOM server with integration of clinical findings and DICOM-conform data encryption.

The transfer of large amounts of medical data within heterogeneous hard and software infrastructures and the exploitation of distributed resources require a fast, secure, and platform-independent data exchange. To avoid costly vendor-specific solutions, a DICOM server was implemented in JAVA. Data access was enabled via internet browser technology. Relevant patient and image acquisition information was extracted from the DICOM images and stored into a relational database. Patient information such as radiological findings were transferred from the Radiological Information System into the database. Image data were accessed either by a fast preview tool or using a JAVA-based DICOM viewer. Since data security mechanisms are not yet part of the DICOM standard, a DICOM-conform encryption of sensitive patient data was implemented. The method allowed a dynamic selection of the data to be encrypted. Integrating this module into the image server enabled the fast and secure transfer of image data across insecure networks as well as long-term storage on CD-Recordables.     

An Automated DICOM Database Capable of Arbitrary Data Mining (Including Radiation Dose Indicators) for Quality Monitoring

The U.S. National Press has brought to full public discussion concerns regarding the use of medical radiation, specifically x-ray computed tomography (CT), in diagnosis. A need exists for developing methods whereby assurance is given that all diagnostic medical radiation use is properly prescribed, and all patients’ radiation exposure is monitored. The “DICOM Index Tracker©” (DIT) transparently captures desired digital imaging and communications in medicine (DICOM) tags from CT, nuclear imaging equipment, and other DICOM devices across an enterprise. Its initial use is recording, monitoring, and providing automatic alerts to medical professionals of excursions beyond internally determined trigger action levels of radiation. A flexible knowledge base, aware of equipment in use, enables automatic alerts to system administrators of newly identified equipment models or software versions so that DIT can be adapted to the new equipment or software. A dosimetry module accepts mammography breast organ dose, skin air kerma values from XA modalities, exposure indices from computed radiography, etc. upon receipt. The American Association of Physicists in Medicine recommended a methodology for effective dose calculations which are performed with CT units having DICOM structured dose reports. Web interface reporting is provided for accessing the database in real-time. DIT is DICOM-compliant and, thus, is standardized for international comparisons. Automatic alerts currently in use include: email, cell phone text message, and internal pager text messaging. This system extends the utility of DICOM for standardizing the capturing and computing of radiation dose as well as other quality measures.Key words: Data extraction, medical informatics applications, radiation dose, database management systems, knowledge base     

Cybersecurity in PACS and Medical Imaging: an Overview

This article provides an overview on the literature published on the topic of cybersecurity for PACS (Picture Archiving and Communications Systems) and medical imaging. From a practical perspective, PACS specific security measures must be implemented together with the measures applicable to the IT infrastructure as a whole, in order to prevent incidents such as PACS systems exposed to access from the Internet. Therefore, the article first offers an overview of the physical, technical and organizational mitigation measures that are proposed in literature on cybersecurity in healthcare information technology in general, followed by an overview on publications discussing specific cybersecurity topics that apply to PACS and medical imaging and present the “building blocks” for a secure PACS environment available in the literature. These include image de-identification, transport security, the selective encryption of the DICOM (Digital Imaging and Communications in Medicine) header, encrypted DICOM files, digital signatures and watermarking techniques. The article concludes with a discussion of gaps in the body of published literature and a summary.     

A Reliable,Low-Cost Picture Archiving and Communications System for Small and Medium Veterinary Practices Built Using Open-Source Technology

Picture Archiving and Communications Systems (PACS) are the most needed system in a modern hospital. As an integral part of the Digital Imaging and Communications in Medicine (DICOM) standard, they are charged with the responsibility for secure storage and accessibility of the diagnostic imaging data. These machines need to offer high performance, stability, and security while proving reliable and ergonomic in the day-to-day and long-term storage and retrieval of the data they safeguard. This paper reports the experience of the authors in developing and installing a compact and low-cost solution based on open-source technologies in the Veterinary Teaching Hospital for the University of Torino, Italy, during the course of the summer of 2012. The PACS server was built on low-cost x86-based hardware and uses an open source operating system derived from Oracle OpenSolaris (Oracle Corporation, Redwood City, CA, USA) to host the DCM4CHEE PACS DICOM server (DCM4CHEE, http://www.dcm4che.org). This solution features very high data security and an ergonomic interface to provide easy access to a large amount of imaging data. The system has been in active use for almost 2 years now and has proven to be a scalable, cost-effective solution for practices ranging from small to very large, where the use of different hardware combinations allows scaling to the different deployments, while the use of paravirtualization allows increased security and easy migrations and upgrades.