Synergy between medical informatics and bioinformatics: facilitating genomic medicine for future health care.

In this paper, we review the results of BIOINFOMED, a study funded by the European Commission (EC) with the purpose to analyse the different issues and challenges in the area where Medical Informatics and Bioinformatics meet. Traditionally, Medical Informatics has been focused on the intersection between computer science and clinical medicine, whereas Bioinformatics have been predominantly centered on the intersection between computer science and biological research. Although researchers from both areas have occasionally collaborated, their training, objectives and interests have been quite different. The results of the Human Genome and related projects have attracted the interest of many professionals, and introduced new challenges that will transform biomedical research and health care. A characteristic of the 'post genomic' era will be to correlate essential genotypic information with expressed phenotypic information. In this context, Biomedical Informatics (BMI) has emerged to describe the technology that brings both disciplines (BI and MI) together to support genomic medicine. In recognition of the dynamic nature of BMI, institutions such as the EC have launched several initiatives in support of a research agenda, including the BIOINFOMED study.

An infrastructure for Integrated Electronic Health Record services: the role of XML (Extensible Markup Language).

BACKGROUND: The sharing of information resources is generally accepted as the key to substantial improvements in productivity and better quality of care. In addition, due to the greater mobility of the population, national and international healthcare networks are increasingly used to facilitate the sharing of healthcare-related information among the various actors of the field. In the context of HYGEIAnet, the regional health telematics network of Crete, an Integrated Electronic Health Record environment has been developed to provide integrated access to online clinical information, accessible throughout the island. OBJECTIVES: To make available comprehensive medical information about a patient by means of incorporating all the distributed and heterogeneous health record segments into an Integrated Electronic Health Record that can be viewed on-line through a unified user interface and visualization environment. METHODS: The technological approach for implementing this Integrated Electronic Health Record environment is based on the HYGEIAnet Reference Architecture, which provides the necessary framework for the reuse of services, components, and interfaces. Seamless presentation of information is achieved by means of the Extensible Markup Language (XML), while its underlying capabilities allow for dynamic navigation according to personalized end-user preferences and authorities. RESULTS: The Integrated Electronic Health Record environment developed in HYGEIAnet provides the basis for consistent and authenticated access to primary information over the Internet in order to support decision-making. Primary information is always kept at the place where it has been produced, and is maintained by the most appropriate clinical information system, contrasting traditional store and forward techniques, or centralized clinical data repositories. CONCLUSIONS: Since documents are much more easily accessible rather than data inside a database, Extensible Markup Language has the potential of becoming a very cheap technology provided, of course, that the underlying Healthcare Information Infrastructure exists. XML can be introduced incrementally and its implementation is completely transparent to the end user.

An open, component-based information infrastructure to support integrated regional healthcare networks.

A fundamental requirement for achieving continuity of care is the seamless sharing of multi-clinical information. Several different technological approaches can be followed to enable the sharing of health record segments. In all cases interoperability between systems is a prerequisite and this requires presently a major technological challenge. Inter-operability can be achieved either through messages or through a more advanced approach based on a federation of autonomous systems. Message based integration is centered mainly on the exchange of HL7 and DICOM messages for achieving the functional integration of clinical information systems (CIS) at institutional or regional level. The federated approach is principally used for facilitating the virtual view of the Integrated Electronic Health Record (I-EHR), without having to replicate unnecessary information. Within the context of HYGEIAnet, which is the regional health telematics network of Crete, both approaches have been utilized for providing end users with seamless access to clinical information. Both are based on an open architecture, which provides the framework for the reuse of standardized common components and public interfaces. This work presents the experiences related to the implementation of "messaging" and "federating" in HYGEIAnet, which are used complementary to each other. A comparison of the two parallel approaches, together with their strengths and weaknesses is described, and evaluation is given from the technological as well as the end users' perspective. Emphasis is given on the technological challenges in developing open, component-based information infra-structure to support integrated service delivery.

Role-based access to patients clinical data: the InterCare approach in the region of Crete.

The basics of a particular Integrated Electronic Health Record (I-EHR) implementation are presented, as realised by the Patient Clinical Data Directory (PCDD) system. PCDD operates within the context of HYGEIAnet, the Integrated Healthcare Telematics Network of Crete. PCDD is based on a federation of autonomous information systems and provides to its authorized users alternative views of the health record as well as access and retrieval services to its geographically distributed segments. The data model of the PCDD is based on the Subjective Objective Assessment Plan (SOAP) model that originates from the primary healthcare domain. Access to detailed information on particular patients healthcare encounters is delivered via role-based authorization privileges and controls. The administration of the national healthcare organizations' business rules, for different user-groups, is made via a specially tailored and developed rule-editor.

Functional and control integration of an ICU, LIS and PACS information system.

The need for collaboration and data sharing among systems dedicated to individual functional areas and user groups has initiated major efforts towards the development of an integrated hospital information system. Major issues in the development of any integrated architecture that incorporates autonomous departmental systems include the development of commonly accepted interaction mechanisms, standardisation, the structure of the computerised patient record, its extensibility, as well as limitations multimedia data impose. This paper presents work done within project IHIS, a nationally funded project for the development of an integrated hospital information system that provides ICU staff with access to both the ICU assisting laboratory information system's data as well as radiological multimedia data.

Pre-hospital health emergency management as an integrated service of the Regional Health Telematics Network of Crete.

In this paper, a Pre-hospital Health Emergency Management System (PHEMS) is presented, which is being developed on the basis of a common reference architecture that has been defined at a European level by partners from ten EU member states in the course of the ongoing HECTOR project. The PHEMS, which is implemented as an autonomous system, will be integrated as an added-value service into the Regional Health Telematics Network of Crete. The PHEMS architecture is based on a 'perception-cognition-action' paradigm.

DIPE: a distributed environment for medical image processing.

DIPE is a distributed environment that provides image processing services over integrated teleradiology services networks. DIPE integrates existing and new image processing software and employs sophisticated execution scheduling mechanisms for the efficient management of computational resources within a distributed environment. It can also be extended to provide various added-value services, such as management and retrieval of image processing software modules, as well as advanced charging procedures based on quality of service. DIPE can be viewed as the natural evolution of the legacy field of medical image processing towards a service over the emergent health care telematics networks.

The I2Cnet service architecture paradigm.

The main objective of the Image Indexing by Content network (I2Cnet) is to provide network-transparent content-based access to medical image archives based on a collection of interoperable Internet/intranet added-value services. This paper discusses I2Cnet, focusing on its service architecture paradigm. I2Cnet services such as image annotation, processing, description, and content-based retrieval, as well as the on-line collaboration service are presented. Exemplary user sessions are used to illustrate how virtual workspaces facilitate the interoperation of I2Cnet services, following the "network computer" approach to information management.

Virtual workspaces in I2Cnet.

The objective of I2Cnet (Image Indexing by Content network) is to provide network-transparent content-based access to medical image archives as an Internet/intranet value-added service. Through a typical web browser, healthcare professionals interact with image collections, browse images similar to a query image, compare these images to images from other collections, and contribute their own images or comments. Specific I2Cnet services available on the World Wide Web (WWW) include image processing and feature extraction, content- and annotation-based search for images and image-related information, and authoring of annotations and image descriptions. Virtual workspaces provide the necessary mechanisms to support user sessions in I2Cnet, providing for service interoperability, persistence, and user interaction. In the course of a user session, which begins with a workspace log-in and ends explicitly with a workspace log-out or implicitly by exiting the browser, virtual workspaces maintain the common context.

WebOnCOLL: medical collaboration in regional healthcare networks.

This paper presents WebOnCOLL, a web-based medical collaboration environment, which has been designed in the context of the regional healthcare network of Crete. WebOnCOLL employs the infrastructure of regional healthcare networks to provide integrated services for virtual workspaces, annotations, e-mail, and on-line collaboration. Virtual workspaces support collaborative concepts like personal web pages, bulletin boards, discussion lists, shared workspaces, and medical case folders. Annotations provide a natural way for people to interact with multimedia content, while e-mail is one of the most popular forms of communication today. On-line collaboration satisfies the need for a more direct form of communication.

I2Cnet medical image annotation service.

I2Cnet (Image Indexing by Content network) aims to provide services related to the content-based management of images in healthcare over the World-Wide Web. Each I2Cnet server maintains an autonomous repository of medical images and related information. The annotation service of I2Cnet allows specialists to interact with the contents of the repository, adding comments or illustrations to medical images of interest. I2Cnet annotations may be communicated to other users via e-mail or posted to I2Cnet for inclusion in its local repositories. This paper discusses the annotation service of I2Cnet and argues that such services pave the way towards the evolution of active digital medical image libraries.

A framework for the integration of distributed autonomous healthcare information systems.

This paper presents a domain-specific framework for the integration of geographically distributed heterogeneous autonomous healthcare information systems. Integration is seen and understood in terms of access to information resources, and in terms of content, structure, and visualization of patient record segments, with the goal of creating a virtual patient record at the medical workstations. The proposed approach covers integration aspects related to presentation, control, data, and function. The architecture and the components of the framework are based on the newly introduced Patient Meta-Record (PMR) concept, but also make use of existing or emerging standards for distributed object-oriented computing and information presentation. At the application and middle-ware layers of the presented healthcare information systems architecture, the PMR concept enhances or enables services for data mediation, distributed directory access, and workflow management. At the bitways layer, high performance networks provide a fast medium, which is indispensable for medical image distribution, collaborative work, hypermedia library applications, and teleconsultation.

I2Cnet: Content-based similarity search in geographically distributed repositories of medical images.

The retrieval of images by content is rapidly gaining acceptance as an important function of image database systems. This paper discusses the architecture of I2Cnet, a network of servers which provide content-based query services through a WWW browser. In I2Cnet, algorithms for the representation, storage, and retrieval of medical images based on different descriptions of image content are implemented using description types. AttributeMatch, a description type supported by I2Cnet, aims to capture the knowledge of medical experts in queries by using a similarity criterion which can be tailored to user preferences. We present results showing the query response time of AttributeMatch, obtained with image classes of various sizes, and the degree of similarity of retrieved images to the query image under different similarity criteria.

Technological advances in teleradiology.

Teleradiology consists of a set of added-value telematic services, implemented over an advanced telecommunications infrastructure and supported by different information technologies and related applications. The main goal of teleradiology is to provide different levels of support for remote diagnostic imaging procedures. This paper considers technological advances in this important area, including a discussion of the various added-value telematic services, applications supporting these services, and the required information technology and telecommunications infrastructure. Teleradiology is also considered in the general context of an integrated regional health telematics network, emphasizing its role and its interaction with other information and networking services.

I2C: a system for the indexing, storage, and retrieval of medical images by content.

Image indexing, storage, and retrieval based on pictorial content is a feature of image database systems which is becoming of increasing importance in many application domains. Medical image database systems, which support the retrieval of images generated by different modalities based on their pictorial content, will provide added value to future generation picture archiving and communication systems (PACS), and can be used as a diagnostic decision support tools and as a tool for medical research and training. We present the architecture and features of I2C, a system for the indexing, storage, and retrieval of medical images by content. A unique design feature of this architecture is that it also serves as a platform for the implementation and performance evaluation of image description methods and retrieval strategies. I2C is a modular and extensible system, which has been developed based on object-oriented principles. It consists of a set of cooperating modules which facilitate the addition of new graphical tools, image description and matching algorithms. These can be incorporated into the system at the application level. The core concept of I2C is an image class hierarchy. Image classes encapsulate different segmentation and image content description algorithms. Medical images are assigned to image classes based on a set of user-defined attributes such as imaging modality, type of study, anatomical characteristics, etc. This class-based treatment of images in the I2C system achieves increased accuracy and efficiency of content-based retrievals, by limiting the search space and allowing specific algorithms to be fine-tuned for images acquired by different modalities or representing different parts of the anatomy.

Supercomputing in medical imaging.

It is suggested that the diagnostic imaging department of the future will make extensive use of computer networks, mass storage devices, and sophisticated workstations at which humans and machines will interact, assisted by techniques of computer vision and artificial intelligence, to achieve integration of multimodality imaging information and expert medical knowledge. Recent developments in medical imaging are described, and manipulation, display, and analysis techniques that are likely to benefit from supercomputing are examined. The following image processing tasks are discussed; restoration of images; spatial and temporal image and image sequence analysis; image restoration; mathematical image reconstruction from projections; and three-dimensional image analysis. Current trends and future efforts are discussed.

An estimation and correction scheme for system imperfections in multiple-echo magnetic resonance imaging.

Multiecho sequences are widely used in MRI because they are an efficient means of acquiring data and they can be used to quantitatively estimate T2. However, the uniformity of each image and the accuracy of each T2 estimate may be corrupted by several instrumental factors such as rf pulse imperfections and static field inhomogeneities. We propose a scheme based on our prior knowledge of the effects of such factors and using the Levenberg-Marquardt method of nonlinear estimation that produces accurate estimates of T2 even in the presence of substantial system imperfections and improves the image quality of later echo images in a multiecho sequence. A further extension of this scheme permits mapping the distribution of the static magnetic field from a single multiecho imaging study of a uniform object. Simulations have been performed to test the efficacy of this scheme and the results are substantiated with experiments performed on a whole-body imager operating at 6.35 MHz.

Errors in the measurements of T2 using multiple-echo MRI techniques. II. Effects of static field inhomogeneity.

The accurate estimation of the spin-spin relaxation time T2 is an important goal in magnetic resonance imaging particularly because it can be used for quantitative tissue characterization. The spin-spin relaxation time T2 may be estimated using multiecho pulse sequences, but the accuracy of the estimate is dependent on the fidelity of the spin-echo amplitudes, which may be severely compromised by rf pulse and static field imperfections. In this paper, the effects of static field inhomogeneities are investigated. The propagation of the errors introduced by off-resonance effects are analyzed through computer simulations and analytical solutions of the Bloch equations. A series of experiments performed on a simple tissue phantom using a whole-body imaging system operating at 6.35 MHz corroborates the simulation and analytical results. For accurate measurements of T2 using a whole-body imaging system it is necessary to correct for these inhomogeneities. A correction scheme which would enable a more accurate estimate of T2 is currently under investigation.

Errors in the measurements of T2 using multiple-echo MRI techniques. I. Effects of radiofrequency pulse imperfections.

In principle, multiple-echo magnetic resonance imaging (MRI) can be used to estimate the spin-spin relaxation time, T2, which can then be used for quantitative tissue characterization. Although multiple echoes can be used to enhance the signal-to-noise ratio in an image, by echo addition, rf pulse imperfections modify the echo amplitudes resulting in significant errors in the estimate of T2. Imperfect 180 degree pulses do not completely invert the transverse magnetization so that the magnitude of the transverse component is reduced and a longitudinal component is generated. Successive application of such imperfect pulses generates many components that interact in a complex manner. The amplitudes of successive echoes are affected whenever the transverse components refocus, whereas the longitudinal components may be rotated into the transverse plane by subsequent pulses and may often add to the image signal or give rise to an image artifact. These effects have been analyzed theoretically and have been demonstrated for a wide range of rf pulse imperfections using both simple and composite pulses, through computer simulations based on the numerical solution of the Bloch equations. The theoretical and simulation results have been substantiated through experiments performed on a mineral oil phantom using a resistive prototype MR scanner operating at 6.35 MHz. In this paper we report the effects of improper pulse amplitude or duration for nonselective rf pulses on resonance. We separately describe the other types of imperfections caused by off-resonance effects and the use of selective pulses.