MAPT and Alzheimer disease: Regarding the individual regional tau retention in tauopathy-related disorders in comparison with the synuclienopathy of PD group, we observed a significantly higher SUVR in all individual regions in AD patients, especially in the frontal and parietal regions (p = 0.035 for the frontal region, p = 0.16 for the temporal region, p = 0.036 for the parietal region (Figures 2B–F and Table 2).