Question Posted 05/30/15:
Dear experts,
May I know if the PIB-PET files contain any information regarding the PIB index (PIB+ or PIB-)? I have looked through them but did not manage to find any information regarding this. Would I have to calculate the PIB index on my own? Your advice is greatly appreciated.
Thank you.
Response posted 05/30/15 by Susan Landau:
PIB +/- status is not available in the U Pitt PIB-PET csv file since the selection of cortical regions to include and the threshold to apply are not universal and are often selected based on specific study hypotheses. A UPitt recommendation for calculating these values is described in Jagust et al. (Alz & Dementia 2010): the frontal, anterior cingulate, precuneus, and parietal region means are averaged together for each subject and then a threshold of 1.5 is applied to determine +/- status. The 1.5 cutoff is derived from a normal sample (Aizenstein et al. Arch Neurol 2008).