Fig. 1
From: Single time point quantitation of cerebral glucose metabolism by FDG-PET without arterial sampling
(A) Scatter plot of the natural logarithm of the arterial FDG concentration as a function of circulation time from a representative subject. Here the measured IDIF is decomposed into its late component (λ3 and its ordinate intercept C) and the intermediate component (λ2 and its ordinate intercept, B), obtained by the method of residuals of the Cλ3 phase. The open circles indicate the residuals of the partial decomposition of Cλ3. In this example, the ordinate intercepts of the linear regressions corresponding to B and C are nearly identical. For clarity of presentation; we omit the corresponding decomposition of the fastest phase, Aλ1. (B) Semi-logarithmic plots of the clearance phase from representative slow, intermediate and fast eliminators. (C) The relationship between λ3 and subject age from (n = 52) patients scanned in Aarhus. (D) The corresponding empirical relationship between the total measured AUC(0–67 min) and the mean arterial concentration measured during the final three frames of the PET recording (Ca(52–67 min). The empirical relationships between the normalized arterial integral measured during the final three frames (theta(52–67 min) as functions of (E) the individual late phase FDG clearance rate constant (λ3) and (F) age of the subjects