Tau positron emission tomography using [18F]THK5351 and cerebral glucose hypometabolism in Alzheimer's disease.

This study aims to evaluate the clinical validity of [18F]THK5351 positron emission tomography (PET) for the assessment of disease progression and symptoms in Alzheimer's disease (AD). Fifty-one patients with AD dementia, 30 patients with amnestic mild cognitive impairment (aMCI), and 43 controls with normal cognition (NC) were included. All subjects underwent [18F]THK5351 PET, 3.0-T magnetic resonance imaging, and detailed neuropsychological tests. Regions of interest and voxel-based statistical analyses were performed. In patients with AD dementia, [18F]THK5351 retention was greater in most association cortices as well as the limbic area compared to NC or aMCI participants. Patients with aMCI also showed higher THK5351 retention in those areas compared to NC. [18F]THK5351 retention significantly correlated with neuropsychological test results. Negative correlations between [18F]THK5351 and [18F] fluorodeoxyglucose were observed in AD dementia and aMCI groups. Mirror images of [18F]THK5351 retention and glucose hypometabolism in [18F] fluorodeoxyglucose were noticeable in the focal variants of AD. [18F]THK5351 PET reflects disease severity and symptoms in AD. Our results suggest [18F]THK5351 is reflective of tau-related AD pathology.