Fig. 2

The simulated AIF for parameters \(A_{1} = 263 \left( {\text{kBq/ml}} \right)\), \(A_{2} = 16 \left( {\text{kBq/ml}} \right)\), \(\mu_{1} = 3.56 \left( {1/{\text{min}}} \right)\) and \(\mu_{1} = 0.029 \left( {1/{\text{min}}} \right)\) at low (c = 0.15) and high noise (c = 0.6) levels and the simulated AIF without noise are shown. b Example of the simulated and estimated AIF for c = 0.15 noise level is shown. Data points denoted by the ‘ + ’ and ‘●’ symbols are measurements taken from LV. Measurements from the 39-48min window (red shaded area) were used to estimate the entire AIF (the red dashed line). c Simulated TACs for \(K_{1} = 0.075\) (ml/g/min), \(k_{2} = 0.15\)(1/min), \(k_{3} = 0.03\) (1/min), and \(v_{b} = 0.03\) at low (c = 0.1) and high (c = 0.4) noise levels and without noise. d Examples of simulated and estimated TACs at c = 0.1 noise level. Data points denoted by the ‘ + ’ and ‘●’ symbols are the TAC measurements. The simulated TAC from the 36–39 min and 48–60 min time frames (the blue shaded area) were used for parameter estimation. The simulated TAC corresponding to the ‘ + ’ symbols were used only for validation