Fig. 3.

Plot of PiB SUVR values versus CSF tau/Aβ42 and agreement statistics. PiB SUVR values are plotted versus CSF tau/Aβ42. Reference lines are drawn at the PiB SUVR cutoff (1.5) used by sites 3 and 4, and the CSF tau/Aβ42 proposed in this study. A least squared regression line is also plotted. The plotting symbols code for the clinical diagnoses. Abbreviations: AD, Alzheimer's disease; CSF, cerebrospinal fluid; HC, healthy control subjects; MCI, mild cognitive impairment; PiB, Pittsburgh Compound B; SUVR, standardized uptake value ratio.