Accuracy of Florbetapir PET Imaging in Alzheimer Disease

Imaging biomarkers have been studied as a means of detecting amyloid-beta (Aβ) pathology in vivo. One such marker, the FDA-approved positron emission tomography (PET) amyloid imaging agent [¹⁸F]florbetapir, previously demonstrated correlation with autopsy findings of Aβ plaque in 35 people with baseline cognitive status ranging from normal to severely demented (JW Neurol Feb 22 2011). Now, the same investigators have conducted a manufacturer-sponsored follow-up study with 24 additional cases that came to autopsy, to assess the accuracy of florbetapir PET imaging.

Of the 59 patients, 46 came to autopsy within 12 months after imaging; the remainder did so within 2 years. The primary analysis compared ratings of florbetapir PET images by five p…