18F-AV45 PET images were obtained on a GE Discovery ST-16-PET/computed tomography scanner after intravenous administration of 370 MBq of flobetapir F-18. Two PET frames (5 min duration, ~50 min post-injection) were averaged and attenuation corrected. The resulting image was normalized to the cerebellum to generate standard uptake value ratios (SUVR) using MIMneuro [30 (link), 31 (link)]. Quantitative SUVR information was generated for 6 ROIs (anterior cingulate, posterior cingulate, precuneus, inferior medial frontal, lateral temporal, and superior parietal cortex). A global SUVR was produced by summing these ROIs.
For classifying individuals as “elevated” or “not elevated” based on PET results, we used a “VisQ Read” described previously and showed an increase in inter-rater reliability 30. Briefly, both a “Visual Read” and a “Quantitative Read” were performed. Raters were then asked to consider the cortical projections, “Visual Read”, and “Quantitative Read”, and provide a final interpretation, or “VisQ Read”, of each scan as “elevated” or “non-elevated”. Individuals were considered to be elevated when two or more raters agreed that the “VisQ Read” was “elevated”.
For classifying individuals as “elevated” or “not elevated” based on PET results, we used a “VisQ Read” described previously and showed an increase in inter-rater reliability 30. Briefly, both a “Visual Read” and a “Quantitative Read” were performed. Raters were then asked to consider the cortical projections, “Visual Read”, and “Quantitative Read”, and provide a final interpretation, or “VisQ Read”, of each scan as “elevated” or “non-elevated”. Individuals were considered to be elevated when two or more raters agreed that the “VisQ Read” was “elevated”.