MAPT and Alzheimer disease: Importantly, detailed clinic-pathologic correlation studies in patients with non-AD tauopathies who underwent [18F]-Flortaucipir PET scans while alive and came to autopsy have further shown the lack of a consistent and robust correlation between levels of in vivo tracer retention and the topographical distribution and burdens of tau lesions quantified at postmortem [15, 26, 32].