All participants underwent an MRI scan of the brain (Siemens Avanto, n = 7; GE Discovery MR750, n = 14; Impax, n = 119; 3T Philips Ingenuity TF PET/MR system, n = 123; 1.5T GE Signa HDxt, n = 21; 3.0T GE Signa HDxt, n = 262; 1.5T Siemens Sonata, n = 27; 3T Toshiba Vantage Titan, n = 119; Vision, n = 1). The protocol included 3D T1-weighted images, 3D T2-weighted images, and 3D T2-weighted fluid-attenuated inversion-recovery (FLAIR) images.18 (link) Visual rating of medial temporal lobe atrophy (MTA) was performed on coronal T1-weighted images averaging scores for the left and right sides (range 0–4).28 (link) Posterior atrophy was rated using sagittal, axial, and coronal planes of T1 and FLAIR-weighted images averaging scores for the left and right sides (range 0–3).29 (link) Global cortical atrophy (GCA) was rated using axial FLAIR images (range 0–3).30 (link) The severity of white matter hyperintensities was determined on the FLAIR sequence using the Fazekas scale (range 0–3).31 (link) Lacunes were defined as deep lesions (3–15 mm) with CSF-like signal on all sequences. They were counted and dichotomized into absent (0) of present (≥1 lacune). Microbleeds were defined as small dot-like hypointense lesions on T2-weighted images. They were also counted and dichotomized into absent (0) or present (≥1 microbleed). An experienced neuroradiologist reviewed all scans.