MAPT and Cognitive impairment: The guiding principles are that dementia experts should be (1) skilled at evaluating, diagnosing, and staging a broad spectrum of cognitive disorders; (2) familiar with the techniques of amyloid and tau PET (including their strengths and limitations); (3) able to interpret the meaning of amyloid and tau PET results in the broader clinical context of individual patients; and (4) able to communicate PET results and their implications for diagnosis and care to patients and families in a safe and effective manner, using best practices for disclosure.