In this issue of The Lancet Neurology , Rinne and colleagues report something of a breakthrough by demonstrating the feasibility of eventually testing the so-called amyloid hypothesis of sporadic Alzheimer's disease in vivo. According to their analysis, a passive immunotherapy protocol with an anti-amyloid-β monoclonal antibody (bapineuzumab) was associated with a decrease in the cerebral PET signal after administration of the amyloid plaque imaging compound carbon-11-labelled Pittsburgh compound ...