Volume 132, Issue 2, Pages 531-542 (February 2007) Quantification of Liver Glucose Metabolism by Positron Emission Tomography: Validation Study in Pigs  Patricia Iozzo, Mikko J. Jarvisalo, Jan Kiss, Ronald Borra, Gratian A. Naum, Antti Viljanen, Tapio Viljanen, Amalia Gastaldelli, Emma Buzzigoli, Letizia Guiducci, Elisabetta Barsotti, Timo Savunen, Juhani Knuuti, Merja Haaparanta–Solin, Ele Ferrannini, Pirjo Nuutila  Gastroenterology  Volume 132, Issue 2, Pages 531-542 (February 2007) DOI: 10.1053/j.gastro.2006.12.040 Copyright © 2007 AGA Institute Terms and Conditions

Figure 1 Study design. Continuous lines (top) indicate plasma sampling for tracer concentration measurements after tracer administration (small arrows); boxes represent PET scanning periods (light gray), liver tissue sampling and organ explantation (dark gray), and study conditions/groups (bottom, white boxes); and thick arrows indicate time points for blood collection (black) and liver Doppler blood flow measurements (gray). Gastroenterology 2007 132, 531-542DOI: (10.1053/j.gastro.2006.12.040) Copyright © 2007 AGA Institute Terms and Conditions

Figure 2 Representative time course of plasma concentrations of [18F]FDG (left) and [2H]G (right) in the artery (white bars), portal vein (gray bars), and hepatic vein (black bars) during the experiments; the expanded representation of early time points in the histogram allows better visualization of rapidly changing tracer concentrations. Gastroenterology 2007 132, 531-542DOI: (10.1053/j.gastro.2006.12.040) Copyright © 2007 AGA Institute Terms and Conditions

Figure 3 Relationship between parameters estimated with 3k and 4k compartmental modeling. Gastroenterology 2007 132, 531-542DOI: (10.1053/j.gastro.2006.12.040) Copyright © 2007 AGA Institute Terms and Conditions

Figure 4 Comparison between HGU, as determined by irreversible or reversible (4k) modeling. *P = .01 versus 3k model. Gastroenterology 2007 132, 531-542DOI: (10.1053/j.gastro.2006.12.040) Copyright © 2007 AGA Institute Terms and Conditions

Figure 5 Dephosphorylation rate contant (k4) (left) and phosphorylation-to-dephosphorylation ratio (k3/k4) (right), showing a progressive response to incremental hyperinsulinemia. *P = .01 versus fasting and P = .10 versus physiologic hyperinsulinemia; **P = .02 versus supraphysiologic and P = .06 versus physiologic hyperinsulinemia. Gastroenterology 2007 132, 531-542DOI: (10.1053/j.gastro.2006.12.040) Copyright © 2007 AGA Institute Terms and Conditions

Figure 6 Representative comparison of graphically derived HKi and HGU values by using the arterial and the dual input, showing strong correlations between the 2 approaches (left panels) with a slight systematic underestimation by the former (right panels). Gastroenterology 2007 132, 531-542DOI: (10.1053/j.gastro.2006.12.040) Copyright © 2007 AGA Institute Terms and Conditions