Tau-positron emission tomography correlates with neuropathology findings

Alzheimers Dement. 2020 Mar;16(3):561-571. doi: 10.1016/j.jalz.2019.09.079. Epub 2020 Jan 4.

Abstract

Introduction: Comparison of tau (flortaucipir) positron emission tomography (FTP-PET) to autopsy is important to demonstrate the relationship of FTP-PET to neuropathologic findings.

Methods: Autopsies were performed on 26 participants who had antemortem FTP-PET. FTP-PET standardized uptake value ratios (SUVRs) were compared to autopsy diagnoses and Braak tangle stage. Quantitative tau burden was compared to regional FTP-PET signal.

Results: Participants with Braak stages of IV or greater had elevated FTP-PET signal. FTP-PET was elevated in participants with Alzheimer's disease. An FTP-PET SUVR cut point of 1.29 was determined to be optimal. Quantitative measurements of hippocampal and temporal lobe tau burden were highly correlated to FTP-PET signal (rho's from 0.61 to 0.70, P ≤ .02).

Discussion: Elevated FTP-PET reflects Braak IV or greater neuropathology. Participants with primary age-related tauopathy and hippocampal sclerosis did not show elevated FTP-PET signal. Secondary neuropathologic diagnoses of Alzheimer's disease neuropathologic change can lead to borderline elevated FTP-PET signal.

Keywords: Alzheimer's disease; Autopsy; Braak tangle stage; PET; Tau; flortaucipir.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Alzheimer Disease / diagnostic imaging*
  • Alzheimer Disease / metabolism
  • Alzheimer Disease / pathology*
  • Autopsy
  • Brain / pathology
  • Female
  • Humans
  • Male
  • Positron-Emission Tomography*
  • tau Proteins / metabolism*

Substances

  • tau Proteins