Fig. 1

The complete schematics for the proposed workflow solution. Summed PET data were used for rigid-body co-registration with the structural MR image, which was spatially normalized to a standard brain template in the MNI space using SyN (and SyN-CCFM in the presence of focal lesion). Once the spatial correspondence was established, a set of ROIs taken from the AAL atlas defined in the MNI space was mapped back to the PET space to extract the cerebellar gray matter (for ¹⁸F-FDDNP). Parametric images of ¹⁵O-water PET (CBF and nCBF, 0–10 min) and ¹⁸F-FDDNP PET [R _I and R _P (0–6 min)] data were constructed using the corresponding methods (see Sect. 2). The same set of ROIs was applied to the CBF and relative-perfusion (R _I and R _P ) images to derive the associated regional values using the combined transformation between template and PET space