Illustration of the idea behind the algorithm in the hybrid deconvolution approach.

<p>R_i(t) curves (black lines) calculated using the IRF of the 2TCM and values of the kinetic rates derived from a study with [¹¹C]DASB for 2 representative regions. Red solid lines indicate the non-displaceable component calculated with a V_ND that is 1/4 the size of (top) and 4 times higher than (bottom) the true underlying V_ND; green dotted lines indicate the non-displaceable component calculated with the true underlying V_ND; blue lines indicate the corresponding specific component. Inset plots are added to allow closer inspection of the first 10 minutes after tracer injection. The time t* is derived from the data as the time point after which the specific component has consistently positive values. IRF: impulse response function; 2TCM: two-tissue compartment model; V_ND: non-displaceable distribution volume.