“…Understanding structural properties, biochemical constituents, and evolution of morphologically diverse Aβ plaques and other AD‐related pathology within and between brain regions in relation to age and development of dementia is needed to guide interpretation of amyloid PET imaging of subjects with DS (Head, Helman, Powell, & Schmitt, ; Neale, Padilla, Fonseca, Holland, & Zaman, ). Compared to the extensive number of amyloid PET studies performed in AD (Cohen et al, ), there are relatively few amyloid PET studies of DS (Annus et al, , ; Cohen et al, ; Cole et al, ; Handen et al, ; Hartley et al, ; Jennings et al, ; Landt et al, ; Lao et al, , ; Mak et al, ; Matthews et al, ; Rafii et al, ; Sabbagh et al, ), even fewer longitudinal studies (Hartley et al, ; Lao et al, ; Tudorascu et al, ), and only one imaging‐to‐autopsy analysis (Sabbagh et al, ). Building upon the understanding that AD and DS brains/pathology are not the same, the purpose of this article is to summarize amyloid PET imaging studies of people with DS in the context of neuropathology defined at autopsy, to guide interpretation of future investigations in larger numbers of subjects with DS over longer periods of time.…”