Cynthia Lemere, PhD, from Harvard Medical School, Boston, MA talks about the role of PET scanning in Alzheimer’s disease at the Alzheimer’s Association International Conference (2017), London, UK. Dr Lemere provides an overview of Dr Sepulcre’s work on using PET scans to track the different spreading pathways of tau and amyloid, and watch the timing of progression, which can ultimately help with treatment.