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Biomedical subjects

F Verhelle

Publications and source records attributed to F Verhelle.

4 recordsLinked to original sources

Picture archiving and communication system (PACS): medical perspectives.

PACS represents the natural evolution from the digital new modalities (US, CT, MRI,...) to a global digital environment, where the film based activities are progressively replaced by their digital counterpart. The advantages of the technique, as well as the drawbacks of the first implementations, are described. The "second generation" PACS concept is presented (modular architecture, progressive implementation, multivendor environment, integration with the Hospital Information System, standardization,...). As "case study", the example of the A.Z.-V.U.B. Hospital Implementation is described.

Computer Communication Networks↗

Picture archiving and communication system (PACS): a progressive approach with small systems.

PACS represents the natural evolution from working with digital modalities (e.g. CT, US, MRI, CR) towards a global digital environment where the film based activities are progressively replaced by their digital counterpart. The advantages of the technique and the drawbacks of the first implementations are described, as well as the recent advances in terms of technology, architecture, medical integration and cost-effectiveness. The so called 'second generation' PACS concept is presented with its features: modular architecture, progressive implementation, multi-vendor environment, integration with the Hospital Information System, standardization. This approach is particularly suited for progressive implementation in an existing hospital, in contrast to the possible top-down construction of a filmless radiology department, as a project for a totally new hospital. The implementation into the university hospital AZ-VUB is described as case study.

Radiology Department, Hospital↗

From archives to picture archiving and communications systems.

Keeping organised and consistent film archives is a well-known problem in the radiological world. With the introduction of digital modalities (CT, MR,...) the idea of archiving the image data in a non common way was born. The aim is to keep the information in digital form from acquisition to destination, e.g. archives, viewing station, teleradiology, a task that was not as easy as some people believed, due to bare technical possibilities and to the lack of standards concerning medical image data. These reasons made it not so common to integrate components of different origins into a digital Picture Archiving and Communication environment. How should we attempt to integrate the analogue examinations? It is ridiculous to exclude the conventional XR-examination that accounts for more than 70% of the total production. We believe that there will be a migration to light-stimulable phosphor plates, but these are not yet user friendly and certainly not cost effective. We have similar problems of immature technology as we had for the digital modalities. In a first attempt the bridge can be crossed, between the two worlds by means of converters (laser scanner, CCD camera). PACS will become a reality in the future as almost all examinations will be digitalized. We are now in a transition period with its inconveniences, but we will gain a lot soon. The migration from piles of films through a computer assisted radiological archiving system to a full digital environment is sketched in a historical survey.

Radiology↗

A method for myelin fiber orientation mapping using diffusion-weighted MR images.

In the past, the anisotropic diffusion of water molecules in white matter in the brain has been correlated to the basic symmetry of the myelin fibers: water diffuses more readily along the fiber direction than perpendicular to it. As a consequence, diffusion sensitized magnetic resonance imaging can be expected to be useful for studying the fiber orientation. In this work, we present a method for exploiting this type of information to map the fiber orientations in the image plane. It makes use of three diffusion-weighted images with sensitizing gradients along x, y and u, an axis at 45 degrees with respect to x and y. The orientation information contained in these images is summarized in a single image representing the angle between the fiber direction and a fixed axis, making use of a cyclic color scale. The method is evaluated using computer simulations for a variety of diffusion weighting strengths and signal-to-noise ratios, tested on a phantom and illustrated on an in vivo example. An extension to the determination of the fiber orientation in three dimensions is also described.

Anisotropy↗