title: Estimation of organ transport function for recirculating indicator dilution curves.
abstract: The transport function of an indicator through an organ allows the calculation of important physiological parameters, but its estimation, especially in the presence of recirculation, can be difficult. In this paper, we estimate the transport function of 3H-mannitol (an extracellular tracer of glucose) in the human leg skeletal muscle. To do so, an indicator bolus is administered into the femoral artery and its recirculating dilution curves are nonuniformly sampled in both the femoral artery and the femoral vein. A new deconvolution-based method is used to simultaneously estimate the indicator transport function and the organ plasma flow. Subsequently, the indicator mean transit time and distribution volume are calculated. The reliability of the method is assessed by Monte Carlo simulation. The ability to estimate parameters, like mean transit time and extracellular distribution volume, is critical to the study of pathophysiologic states such as diabetes, insulin resistance, and hypertension.
authors.affiliation: Department of Electronics and Informatics, University of Padova, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Sparacino
authors.forename: R
authors.initials: R
authors.lastname: Bonadonna
authors.forename: H
authors.initials: H
authors.lastname: Steinberg
authors.forename: A
authors.initials: A
authors.lastname: Baron
authors.forename: C
authors.initials: C
authors.lastname: Cobelli
mesh_terms: D015982:Bias; D001775:Blood Circulation; D001810:Blood Volume; D005263:Femoral Artery; D005268:Femoral Vein; D006801:Humans; D007201:Indicator Dilution Techniques / Q000295:instrumentation; D007866:Leg / Q000098:blood supply; D008353:Mannitol / Q000097:blood / Q000493:pharmacokinetics*; D008657:Metabolic Clearance Rate; D009010:Monte Carlo Method; D018482:Muscle, Skeletal / Q000502:physiology*; D012016:Reference Values; D015203:Reproducibility of Results; D018709:Statistics, Nonparametric; D013997:Time Factors; D014018:Tissue Distribution; D014316:Tritium / Q000097:blood / Q000493:pharmacokinetics*
chemical_list: D014316:Tritium; D008353:Mannitol