MOESM1 of Frequency, associated factors and outcome of multi-drug-resistant intensive care unit-acquired pneumonia among patients colonized with extended-spectrum β-lactamase-producing Enterobacteriaceae

Additional file 1. . Additional results (Tables S1 to S6)

Errors in Net Uptake Rates Estimated by the Patlak and Sokoloff Methods.

<p>Contour plot showing the effect of k₅ and k₅/k₆ on the absolute errors of Ki in the Sokoloff (Δ_KiS = Ki_S-Ki_F [10⁻³/min]) and the Patlak methods (Δ_KiP = Ki_P-Ki_F [10⁻³/min]) as compared to the four-compartment model (contour lines) in simulations of a healthy lung (LPS−, Lav−) and of a lung exposed to systemic endotoxin and bronchoalveolar lavage (LPS+, Lav+), original data points of the “LPS−, Lav−” simulation (•) and the “LPS+, Lav+” simulation (▴). Note that in both simulated conditions Δ_KiS is larger than Δ_KiP. Both the Patlak method and the Sokoloff model show higher errors in the “LPS+, Lav+” simulation.</p

Four-Compartment Model.

<p>Schematic of the lung-specific four-compartment model of ¹⁸F-FDG kinetics including an extra-vascular extra-cellular compartment to account for ¹⁸F-FDG that is not directly available for phosphorylation, such as ¹⁸F-FDG in lung water. Note the functional distinction between extra-vascular extra-cellular compartment, which is a non-substrate compartment so that ¹⁸F-FDG is not available for phosphorylation, and the precursor compartment where ¹⁸F-FDG is available for phosphorylation.</p

Estimation Errors as a Function of k₅.

<p>(A) Relative errors of k₁ (ε_k1 = (k_1S-k_1F)/k_1F ·100), k₂ (ε_k2 = (k_2S-k_2F)/k_2F ·100), k₃ (ε_k3S = (k_3S-k_3F)/k_3F·100) and F_e (ε_Fe = (F_e-F_ei)/F_ei·100) versus k₅ at a k₅/k₆ ratio of 0.14, 0.69 and of 1.24; (B) absolute errors of k₁ (Δ_k1 = k_1S-k_1F), k₂ (Δ_k2 = k_2S-k_2F), k₃ (Δ_k3S = k_3S-k_3F) and F_e (Δ_Fe = F_e-F_ei) versus k₅ at a k₅/k₆ ratio of 0.14, 0.69 and of 1.24.</p

Parameters Defining the Extra-cellular Extra-vascular Compartment.

<p>Relationship between k₅ and k₅/k₆ of three isogravitational ROIs in control lungs (LPS−, Lav−), lungs exposed to bronchoalveolar lavage (LPS−, Lav+), lungs exposed to systemic endotoxin (LPS+, Lav−) and lungs exposed to endotoxin and lavage (LPS+, Lav+). The highlighted gray area illustrates the range over which k₅ and k₅/k₆ were varied in the simulations (0–75^th percentile of all experimental data).</p

Tracer Kinetics Parameters of the Patlak, the Sokoloff and the Four- Compartment Methods and experimental Wet-to-Dry Ratio.

<p>Values are shown as median [interquartile range 25–75%];</p>***<p>p<0.001.</p

Absolute and relative Errors of estimated Parameters for the Patlak and the Sokoloff Model.

<p>Values are shown as median [interquartile range 25–75%];</p>**<p>p<0.01,</p>***<p>p<0.001 as compared to the “LPS−, Lav−” simulation;</p>†††<p>p<0.001 as compared to the corresponding absolute respective relative error in Ki_S.</p

Compartment Activities and Estimation Errors as a Function of k₅.

<p>(A) Integral of the compartment activity according to the Sokoloff model over the imaging duration (∫C_S,fit), divided by the integral of the activity of that compartment in the simulation (∫C_F,sim) for the substrate (∫Cs_S/∫Cs_F) and the metabolized compartments (∫Cm_S/∫Cm_F) versus k₅ at a k₅/k₆ ratio of 0.3 and of 1.1; (B) relative errors of Ki (ε_KiS = (Ki_S-Ki_F)/Ki_F·100), k₃ (ε_k3S = (k_3S-k_3F)/k_3F·100) and F_e (ε_Fe = (F_e-F_ei)/F_ei·100) versus k₅ at a k₅/k₆ ratio of 0.3 and of 1.1.</p

Bland-Altman Plots of k₃ and F_e.

<p>Bland-Altman plots comparing (A) the net ¹⁸F-FDG uptake rate Ki_S of the Sokoloff model with Ki_F of the four-compartment model, (B) the intracellular distribution volume F_e of the Sokoloff model with F_ei of the four-compartment model and (C) k_3S of the Sokoloff model with k_3F the four-compartment model of three isogravitational ROIs in healthy lungs (LPS−, Lav−), lungs exposed to bronchoalveolar lavage (LPS−, Lav+), lungs exposed to systemic endotoxin (LPS+, Lav−) and lungs exposed to systemic endotoxin and bronchoalveolar lavage (LPS+, Lav+). Note, that in the “LPS+, Lav+” condition the Sokoloff model tends to overestimate the fractional distribution volume of the precursor pool (F_e) at high mean values of that volume and to underestimate the hexokinase activity (k_3S) at high mean values of k₃. In contrast, the net uptake rates Ki were similar for the four-compartment and Sokoloff models in high Ki ranges.</p

Errors in k₃ and F_e Estimated by the Sokoloff Method.

<p>Errors in both k₃ (Δ_k3S = k_3S-k_3F [10⁻²/min]) as filled contours and F_e (Δ_Fe = F_e-F_ei 10⁻¹) as contour lines as function of k₅/k₆ and k₅ in simulations of a healthy lung (LPS−, Lav−) and of a lung exposed to systemic endotoxin and bronchoalveolar lavage (LPS+, Lav+). Note that Δ_k3 is higher in the simulation of the healthy lung and Δ_Fe is higher in the simulation of the injured lung.</p