Figure 1.

Cortical patterns of 18F T807 binding. Coronal ¹⁸F T807 PET images (top row) and whole-brain surface renderings of SUVR (second row) from 3 normal (CN) and 4 impaired (2 MCI and 2 AD dementia) participants. Top row A. A 71 year-old CN with low Aβ by PiB PET (DVR=1.0) had low, non-specific ¹⁸F T807 binding in cortex, consistent with a Braak Stage less than III/IV. B. A 74 year-old CN with high Aβ (DVR=1.2) with ¹⁸F T807 binding in inferior temporal cortex, left>right, consistent with Braak Stage III/IV. C. A 79 year-old CN, high Aβ (DVR=1.8) had binding in inferior temporal neocortex, consistent with Braak Stage of III/IV. B and C show focally intense subcortical uptake that is likely due to off-target binding (see Discussion). D–G. Cognitively impaired participants all with high Aβ and with successively greater levels of cortical ¹⁸F T807 binding successively involving temporal, parietal, frontal and occipital cortices. Second row: ¹⁸F T807 SUVR calculated at vertices (see Methods) indicating the extent of cortical binding, with left hemisphere views (lateral, inferior, superior, medial) at left. The 52 year-old AD dementia patient (G) showed confluent ¹⁸F T807 binding that is nearly pancortical, sparing only portions of primary cortex and consistent with Braak Stage V/VI.

MMSE= mini-mental state exam

PiB= Pittsburgh Compound B

DVR= distribution volume ratio, mean cortical

SUVR= standardized uptake value, cerebellar reference

Dx= classification (CN, clinically normal; MCI, mild cognitive impairment; AD mild AD dementia)

PET Braak= Estimate of Braak Stages is based on the anatomic pattern of T807 binding assessed visually and quantitatively in regions and full volume data.