The proton relaxation times, T1 and T2, of water in Sephadex gels, exhibiting pores of varying size (i.e., with exclusion limits of molecular weight between 10(3) and 10(5)) and water contents in the range 30 to 70% (w/w, weight of water to total weight), were measured at 20 MHz in the temperature range 5 to 50 degrees C. Multiexponential analysis of the relaxation curves revealed the existence of two relaxation components in all gel systems. A component with long T1 and T2 (T1,1 and T2,1) is associated with a large water fraction alpha 1,1 and alpha 2,1 and a component with short T1 and T2 (T1,2 and T2,2) with a small water fraction alpha 1,2 and alpha 2,2. An analysis of the temperature behavior of the relaxation components gives insight into the relaxation mechanisms. The relaxation process in water, compartmentalized in the gel matrix, is mainly controlled by dipole-dipole interactions. In addition, proton exchange processes between hydration water and hydroxyl groups of the matrix chain contribute under specific conditions and lead to a dramatic enhancement of the relaxation rate. In particular, for gels with small pores and with low water content proton exchange is observed. Compartments of water in gels could be models for compartments of water in biological tissues.

SummaryBackground: For more than 30 years, there has been close cooperation between Japanese and German scientists with regard to information systems in health care. Collaboration has been formalized by an agreement between the respective scientific associa tions. Following this agreement, two joint workshops took place to explore the similarities and differences of electronic health record systems (EHRS) against the background of the two national healthcare systems that share many commonalities. Objectives: To establish a framework and requirements for the quality of EHRS that may also serve as a basis for comparing different EHRS.Methods: Donabedian's three dimensions of quality of medical care were adapted to the outcome, process, and structural quality of EHRS and their management. These quality dimensions were proposed before the first workshop of EHRS experts and enriched during the discussions. Results: The Quality Requirements Framework of EHRS (QRF-EHRS) was defined and complemented by requirements for high quality EHRS. The framework integrates three quality dimensions (outcome, process, and structural quality), three layers of information systems (processes and data, applications, and physical tools) and three dimensions of information management (strategic, tactical, and operational information management). Conclusions: Describing and comparing the quality of EHRS is in fact a multidimensional problem as given by the QRF-EHRS framework. This framework will be utilized to compare Japanese and German EHRS, notably those that were presented at the second workshop.

Parameter-selective imaging for tissue characterization is performed at low magnetic fields (0.24-0.28 T) employing echo trains with a large number of echoes (less than or equal to 50), high-power pulses, and the projection reconstruction method. Preprocessing of the raw echoes is important for the quality of the echo images which are the bases for further evaluation and generation of parameter-selective images. Two new algorithms are implemented in the image preprocessing routine TOMIKON: Echo shape analysis and image size adjustment. Echo shape analysis allows the detection and the removal of spikes in the echo signals to avoid image artifacts. Image size adjustment is performed by expanding and contracting the time basis of the echoes resulting in a size normalization of the echo images, an indispensable condition for generating diffusion images.

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WORKS, a software system being developed by rtium SAMMIE, aims to provide an environwhich radiologists and neuroclinicians can rain images from different modalities together related signals and brain models and atlases. tive versions will provide the Digital Light-1 Workbench, with facilities extended to Advanced Visual Workbench, capable of a1 brain objects. The overall sysrem lace allowing for integration of modumembers. The geometric, sraic models have been &fined and are ualisation and editing modules for ta are fully advanced, Work is in brain objects by segmentation. critical modules and the use of rn database techniques will insure acceptable speed