title: A model for transit time distributions through organs that accounts for fractal heterogeneity.
abstract: It has been shown that density functions of organ transit time distributions of vascular markers (washout curves) are characterized by a power-law tail, reflecting the fractal nature of the vascular network. Yet, thus far, no closed-form model is available that can be fitted to such organ outflow data. Here we propose a model that accounts for the existing data. The model is a continuous mixture of inverse Gaussian densities, implying flow heterogeneity in the organ. It has been fitted to outflow data from the rabbit heart and rat liver. The power-law decay with exponent -3 observed in the heart, corresponds to an intra-organ flow distribution with a relative dispersion of about 35%.
authors.affiliation: Department of Pharmacology, Martin Luther University Halle-Wittenberg, D-06097 Halle, Germany. michael.weiss@medizin.uni-halle.de
authors.forename: Michael
authors.initials: M
authors.lastname: Weiss
mesh_terms: D000818:Animals; D017709:Fractals; D007202:Indicators and Reagents / Q000493:pharmacokinetics*; D008099:Liver / Q000378:metabolism; D008657:Metabolic Clearance Rate; D008954:Models, Biological; D009206:Myocardium / Q000378:metabolism; D011817:Rabbits; D011849:Radioactive Tracers; D011865:Radioisotope Dilution Technique; D051381:Rats; D014018:Tissue Distribution
chemical_list: D007202:Indicators and Reagents; D011849:Radioactive Tracers