Fig. 6.

Correlations between biochemical measures and in vivo DVR values from the right hemisphere of each case. Graphs show correlations of Aβ1–42 and Aβ1–40 (ELISA) levels and [H-3]PiB binding in postmortem brain homogenates with in vivo [C-11]PiB PET retention values obtained from [C-11]PiB(−) and [C-11]PiB(+) cases. The filled triangles represent the [C-11]PiB(−) case, and the open circles represent the [C-11]PiB(+) case. The circles above the line at DVR = 1.4 represent nine brain areas that were positive by in vivo [C-11]PiB PET (i.e., DVR greater than established cutoffs for the particular brain area [1]), and symbols below the line at DVR = 1.2 represent brain areas with only background PiB retention. The area between the DVR range 1.2–1.4 is a region of questionable PiB positivity, and it contains the hippocampus and subiculum/entorhinal regions from the [C-11]PiB(+) case. a In the [C-11]PiB(−) case, Aβ1–42 concentrations did not exceed 500 pmol/g in all areas except in the frontal pole region (788 pmol/g, FP); this value is near the 900 pmol/g concentration measured in the caudate (CD) region at the lower end of the value range in clearly positive brain regions from the [C-11]PiB(+) case. b The frontal pole region (FP) and three other neocortical areas in the [C-11]PiB(−) case had Aβ1–40 concentrations in the middle of the range of Aβ1–40 concentration values from the [C-11]PiB(+) case, while in all other regions from the [C-11]PiB(−) case Aβ1–40 values were at background levels. c [H-3]PiB binding for all brain areas in the [C-11]PiB(−) case was at background levels. CB cerebellum