title: Tracer kinetics of forearm endothelial function: comparison of an empirical method and a quantitative modeling technique.
abstract: Forearm Endothelial Function (FEF) is a marker that has been shown to discriminate patients with cardiovascular disease (CVD). FEF has been assessed using several parameters: the Rate of Uptake Ratio (RUR), EWUR (Elbow-to-Wrist Uptake Ratio) and EWRUR (Elbow-to-Wrist Relative Uptake Ratio). However, the modeling functions of FEF require more robust models. The present study was designed to compare an empirical method with quantitative modeling techniques to better estimate the physiological parameters and understand the complex dynamic processes. The fitted time activity curves of the forearms, estimating blood and muscle components, were assessed using both an empirical method and a two-compartment model. Although correlational analyses suggested a good correlation between the methods for RUR (r=.90) and EWUR (r=.79), but not EWRUR (r=.34), Altman-Bland plots found poor agreement between the methods for all 3 parameters. These results indicate that there is a large discrepancy between the empirical and computational method for FEF. Further work is needed to establish the physiological and mathematical validity of the 2 modeling methods.
authors.affiliation: Department of Nuclear Medicine, Montreal Heart Institute and Concordia University, Canada. shirleyzhao27@yahoo.ca
authors.forename: Xueli
authors.initials: X
authors.lastname: Zhao
authors.forename: Andre
authors.initials: A
authors.lastname: Arsenault
authors.forename: Kim L
authors.initials: KL
authors.lastname: Lavoie
authors.forename: Bernard
authors.initials: B
authors.lastname: Meloche
authors.forename: Simon L
authors.initials: SL
authors.lastname: Bacon
mesh_terms: D002318:Cardiovascular Diseases / Q000000981:diagnostic imaging*; D004730:Endothelium, Vascular / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D005542:Forearm / Q000000981:diagnostic imaging*; D006801:Humans; D007700:Kinetics; D008297:Male; D008955:Models, Cardiovascular; D009943:Organophosphorus Compounds / Q000494:pharmacology*; D015609:Organotechnetium Compounds / Q000494:pharmacology*; D011849:Radioactive Tracers; D011877:Radionuclide Imaging / Q000379:methods; D019275:Radiopharmaceuticals / Q000494:pharmacology*
chemical_list: D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D011849:Radioactive Tracers; D019275:Radiopharmaceuticals; C078700:technetium tc-99m tetrofosmin