Biomedical subjects

S C Orphanoudakis

Publications and source records attributed to S C Orphanoudakis.

24 records · Page 2Linked to original sources

PubMedDate not supplied

Preliminary evaluation of display format effects on perceptibility in a low contrast ultrasound test object.

A phantom consisting of a gel closely resembling human liver on B-mode scanning, and containing a rounded zone of decreased echogenicity, was used to create a series of B-mode ultrasonic images containing simulated "lesions" in random locations on the final recorded image. A homogeneous gel phantom was used to create a series of blank images. Images were recorded in three display formats: conventional white on black background, conventional black on white background, and black on a white background with luminance normalized to that of the conventional white on black image. Six subjects were presented with a randomized series of scans in the 3 display formats, and receiver operating characteristic analysis was used to assess the effect of display format on low-contrast detectability. Detectability of low-contrast "lesions" was lower in a high contrast image with black on white background compared to the medium contrast image in white on black format. Detectability with the black on white format having normalized luminance was generally intermediate between that observed for the two conventional formats.

Evaluation Studies as Topic↗

PubMedDate not supplied

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.

Databases as Topic↗

PubMedDate not supplied

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.

Abstracting and Indexing↗

PubMedDate not supplied

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.

Computer Communication Networks↗

PubMedDate not supplied

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.

Computer Communication Networks↗

PubMedDate not supplied

Brominated radiopaque liposomes: contrast agent for computed tomography of liver and spleen: a preliminary report.

Contrast enhancement of liver and spleen in the dog was obtained after intravenous administration of brominated radioopaque liposomes (ROL) (1-5 micron in diameter. Computed tomographic (CT) numbers generated before and after 3 hours of ROL administration demonstrated an increase in hepatic attenuation. ROL are biodegradable lipid vesicles that can be subjected to further physicochemical modifications (size, charge composition) that alter their biodistribution and pharmacokinetics. These changes can result in improved hepatosplenic contrast enhancement.

Animals↗