Perfusion-Phase [18F]THK5351 Tau-PET Imaging as a Surrogate Marker for Neurodegeneration.

We aimed to test if early, perfusion phase tau-PET imaging with [18F]THK5351 might substitute for [18F]FDG PET information on neurodegeneration, as has been previously shown for amyloid-tracers. A patient with cognitive impairment and positive amyloid-PET was examined by [18F]THK5351 tau-PET and [18F]FDG PET. The pattern of early phase of [18F]THK5351 uptake was compared to [18F]FDG visually and by the dice similarity coefficient. Visual inspection of axial slices and stereotactic-surface projection indicated a striking agreement between combined 0-2 min p.i. perfusion images of [18F]THK5351 and standard [18F]FDG 30-60 min p.i. A two-phase protocol of [18F]THK5351 PET might give information on neurodegeneration and tau pathology in a single session.