Negative C-11-PIB PET Predicts Lack of Alzheimer's Disease Pathology in Postmortem Examination

Abstract

Our aim was to assess whether in vivo C-11-PIB negative memory-impaired subjects may nonetheless exhibit brain Alzheimer's disease (AD) pathology. We re-evaluated the PET images and systematically characterized the postmortem neuropathology of six individuals who had undergone clinically indicated amyloid PET. The single case with negligible amyloid-beta (A beta) pathology had Lewy body disease, where concomitant AD changes are often seen. Further, the subject's plaques were predominantly diffuse. The predictive value of a negative C-11-PIB scan appears to be good, even in memory-impaired populations. Our results suggest that considerable neuritic A beta plaque pathology in the absence of specific/cortical C-11-PIB binding upon PET is unlikely.