Data analysis
The list-mode data from the PET scans were reconstructed by filtered back projection into 21 successive frames (6 × 10 s, 2 × 30 s, 3 × 1 min, 2 × 2 min, 2 × 3 min, 3 × 5 min, and 3 × 10 min). Attenuation correction was performed by the separate ellipse algorithm (ECAT EXACT HR + ) or by a low-dose CT (Biograph mCT). PMOD (version 3.8; PMOD Technologies LLC) was used for image processing and pharmacokinetic modeling. The summed PET images of each participant (frames 1–21) were aligned to the MRI scan of the same participant. Hereafter, a 6-tissue probability map normalization of the individual MRI scan into the Montreal Neurological Institute (MNI) space was performed (Ashburner & Friston, Two-tissue compartment modeling was used to calculate binding potential (BPCorrection for the individual delay and an individually fitted whole blood volume was applied. It was assumed that the distribution volume of the non-displaceable compartment (