caa a22 4500 469122587 CHVBK 20180323133143.0 cr unu---uuuuu 170328e19921101xx s 000 0 eng 10.1007/BF02368613 doi (NATIONALLICENCE)springer-10.1007/BF02368613 Computationally efficient algorithms for convection-permeation-diffusion models for blood-tissue exchange [Elektronische Daten] [James Bassingthwaighte, I. Chan, C. Wang] Analysis of data on tissue depositions obtained by positron tomographic or NMR imaging, or of multiple tracer outflow dilution curves, requires fitting data with models composed of aggregates of capillary-tissue units. These units account for heterogeneities of flows and multisolute exchanges between longitudinally distributed regions across capillary and cell barriers within an organ. Because the analytic solutions to the partial differential equations require convolution integration, solutions are obtained relatively efficiently by a fast numerical method. Our approach centers on the use of a sliding fluid element algorithm for capillary convection, with the time step set equal to the length step divided by the fluid velocity. Radial fluxes by permeation between plasma, interstitial fluid, and cells and axial diffusion exchanges within each time step are calculated analytically. The method enforces mass conservation unless there is regional consumption. Solution for a 2-barrier, 3-region model, accurate to within 0.5%, are 100 to 1000 times faster than the corresponding, purely analytic solution, and over 10,000 times for a 4-region model. Applications include multiple indicator dilution studies of kinetics of transcapillary exchange and positron emission tomographic studies of the mechanisms of substrate transport into cells of organsin vivo. Pergamon Press Ltd., 1992 Blood-tissue exchange nationallicence Capillary permeability nationallicence Pharmacokinetics nationallicence Cellular uptake nationallicence Volumes of distribution nationallicence Interstitial space nationallicence Intracellular consumption nationallicence Organ uptake and washout nationallicence Blood flow nationallicence Bassingthwaighte James Center for Bioengineering WD-12, University of Washington, 98195, Seattle, WA aut Chan I. Center for Bioengineering WD-12, University of Washington, 98195, Seattle, WA aut Wang C. Department of Mathematics, Michigan State University, East Lansing, MI aut Annals of Biomedical Engineering Kluwer Academic Publishers 20/6(1992-11-01), 687-725 0090-6964 20:6<687 1992 20 10439 https://doi.org/10.1007/BF02368613 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02368613 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Bassingthwaighte James Center for Bioengineering WD-12, University of Washington, 98195, Seattle, WA aut NATIONALLICENCE 700 1- Chan I. Center for Bioengineering WD-12, University of Washington, 98195, Seattle, WA aut NATIONALLICENCE 700 1- Wang C. Department of Mathematics, Michigan State University, East Lansing, MI aut NATIONALLICENCE 773 0- Annals of Biomedical Engineering Kluwer Academic Publishers 20/6(1992-11-01), 687-725 0090-6964 20:6<687 1992 20 10439 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer