Tau Imaging in Aging and Early Alzheimer Disease

To investigate ¹⁸F T807 as a biomarker for tau pathology in Alzheimer disease (AD), researchers recruited 75 participants of the Harvard Aging Brain Study. Of the 75 patients (mean age, 73), 56 were cognitively normal, 13 had mild cognitive impairment (MCI), and 6 had dementia based on clinical evaluation that included the Mini-Mental State Examination, Clinical Dementia Rating scale, and Logical Memory delayed recall test. Tau deposition was identified using standardized uptake value ratio from ¹⁸F T807 positron emission tomography imaging, and amyloid deposition was identified using distribution volume ratio from ¹¹C Pittsburgh Compound B (PiB) imaging.

Corresponding to the Braak neuropathology staging scheme for AD, tau deposition was min…