Multimodal PET Imaging of Amyloid-β

^Participants underwent ¹⁸F-flutemetamol PET and ¹⁸F-RO948 PET on Discovery MI scanners (GE healthcare). ¹⁸F-flutemetamol PET images were acquired 90 to 110 min after injection of 185 MBq ¹⁸F-flutemetamol, whereas ¹⁸F-RO948 PET images were acquired 70 to 90 min after injection of 370 MBq ¹⁸F-RO948. Pre-processing and generation of standardized uptake value ratio (SUVRs) maps were carried out as previously described.^{32 (link),33 (link)18}F-Flutemetamol scans were normalized using the Pons as reference region, whereas ¹⁸F-RO948 images were referenced to the inferior cerebellar grey matter. For all subjects, Aβ status was defined based on the average SUVR values from a cortical composite using a previously published cut-off of 0.53.^{32 (link)}