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Biomedical subjects

O Ratib

Publications and source records attributed to O Ratib.

62 records · Page 4Linked to original sources
PubMedDate not supplied

Detection and quantification of valvular heart disease with dynamic cardiac MR imaging.

Magnetic resonance (MR) imaging is rapidly gaining acceptance as an accurate, reproducible, noninvasive method for optimal assessment of structural and functional parameters in patients with valvular heart disease. The severity of valvular regurgitation can be evaluated with cine gradient-echo MR imaging, which allows measurement of the area of the signal void corresponding to the abnormal flow jet. Alternatively, this modality can be used to obtain ventricular volumetric measurements and calculate the regurgitant fraction, or velocity-encoded cine (VEC) MR imaging can be used to quantify regurgitant blood flow. The severity of valvular stenosis can be determined by evaluating the flow jet and associated findings with either modality or by using VEC MR imaging to calculate the transvalvular pressure gradient and valve area. Dynamic MR imaging allows accurate assessment of ventricular function and comprehensive evaluation of pathophysiologic changes. In addition, good interstudy reproducibility suggests a role for VEC MR imaging in assessing the effects of therapeutic intervention and monitoring regurgitant fraction, thereby helping in surgical planning and the prevention of ventricular dysfunction. With greater cost-effectiveness and the increasing availability of new hardware and more advanced techniques, MR imaging will become a routine procedure in valvular heart disease.

Blood Flow Velocity↗
PubMedDate not supplied

Computer-aided design and modeling of workstations and radiology reading rooms for the new millennium.

Three-dimensional (3D) computer modeling, simulation, and rendering techniques were used to redesign the diagnostic workstations and radiology reading rooms for a proposed hospital with particular attention given to lighting conditions, noise reduction, and optimal use of limited workspace. The results were presented to a panel of multidisciplinary experts and iteratively improved and redesigned with the development or addition of new design criteria or requirements. These 3D techniques allowed faster, more efficient design and presentation of multiple options than is possible with traditional two-dimensional drawings, thereby expediting decision making and resulting in significant savings. The current workstation designs can easily be developed and implemented with available technology at a reasonable cost. They can also accommodate anticipated advances in computer and display technology as well as new imaging paradigms (eg, changes in keyboard and control ergonomics such as adjustable virtual keys on touch-sensitive screens, digital drawing tablets for annotations and controls, direct film digitizing, personal identification devices, offline media readers such as compact disks and digital videodisks, and speech recognition and voice activation). Use of 3D techniques in designing other parts of the radiology department (eg, examination rooms, technologists' areas, physicians' offices) could greatly improve and facilitate the design and implementation of complex settings in these work areas.

Computer Simulation↗
PubMedDate not supplied

Unimage, a new RIS for the DIOGENE 2 environment at Geneva Cantonal University Hospital.

The effective management of a radiology department depends on adequate computing tools for imaging specialists--radiologists and technicians--and administrators. The rapid evolution of imaging techniques in radiology requires flexible systems for describing the daily operation of a service and accessing data generated by every possible source. In order to compensate for the insufficiencies of our current radiology information system (RIS), and within the framework of the migration towards the DIOGENE 2 hospital information system, a new RIS, named Unimage, has been implemented at the Cantonal University Hospital of Geneva. Unimage has been designed not only to fit the current and future needs of the radiology department, but also to operate in different services, i.e. diagnostic radiology, nuclear medicine and therapy radiology. Among its functionalities, Unimage offers a simple two-way data communication with the PACS world. The technical choices we have made in the design of the new RIS include a distributed environment, as well as a graphical (X/Motif) user interface. The main functionalities and the technical implementation of Unimage are described in this paper.

Appointments and Schedules↗
PubMedDate not supplied

PAPYRUS 3.0: DICOM-compatible file format.

This paper describes the PAPYRUS 3.0 file format based on the new DICOM 3.0 Standard which addresses the open interchange of medical images in files or on removable storage media. This specific implementation of the DICOM standard is intended as a generic solution for interchange of multi-modality medical images on removable media. It can also be used for convenient exchange of image data between different computer systems through industry standard file transfer mechanisms. Finally it can also be used for storage and archiving of medical image data in a DICOM-compatible format.

Computer Communication Networks↗
PubMedDate not supplied

Desktop image analysis: workstations of the future.

We report the use of an interactive graphics-oriented workstation to explore quantitative information extracted from medical images. At the University of California at Los Angeles, a Macintosh II personal computer operates as a stand-alone system and images are imported from a central PACS (picture archiving and communication system) server through an Ethernet network. The image-analysis program contains a complete set of general-purpose tools for image manipulation and processing, as well as specific tools for clinical analysis of cardiac and vascular images obtained by various techniques. Most of these features were designed to communicate information through color-coded graphic displays. Ten novice users were given a brief introduction to the program and asked to perform eight analytic tasks. The overall success rate was 95%, and the subjects considered the program easy to use without a manual or formal training. We conclude that with a well-designed graphic interface, physicians without training in the use of computers can easily learn to manipulate and analyze medical images.

Computer Graphics↗
PubMedDate not supplied

An integrated hospital information system in Geneva.

Since the initial design phase from 1971 to 1973, the DIOGENE hospital information system at the University Hospital of Geneva has been treated as a whole and has retained its architectural unity, despite the need for modification and extension over the years. In addition to having a centralized patient database with the mechanisms for data protection and recovery of a transaction-oriented system, the DIOGENE system has a centralized pool of operators who provide support and training to the users; a separate network of remote printers that provides a telex service between the hospital buildings, offices, medical departments, and wards; and a three-component structure that avoids barriers between administrative and medical applications. In 1973, after a 2-year design period, the project was approved and funded. The DIOGENE system has led to more efficient sharing of costly resources, more rapid performance of administrative tasks, and more comprehensive collection of information about the institution and its patients.

Computer Systems↗
PubMedDate not supplied

Osiris: a medical image-manipulation system.

We designed a general-purpose computer program, Osiris, for the display, manipulation, and analysis of digital medical images. The program offers an intuitive, window-based interface with direct access to generic tools. Characterized by user-friendliness, portability, and extensibility, Osiris is compatible with both Unix-based and Macintosh-based platforms. It is readily modified and can be used to develop new tools. It is able to monitor the entries made during a work session and thus provide data on its use. Osiris and its source code are being distributed, free of charge, to universities and research groups around the world.

Image Processing, Computer-Assisted↗