MAPT and Alzheimer disease: In patients with an etiological diagnosis of non-AD already supported by a first PET scan, a further change in diagnosis was observed in 100% (2/2) of patients after a positive tau-PET, and in 44% (7/16) after a positive amyloid-PET, with no difference between exams (χ2 = 0.56, p = 0.453).