In vivo quantification of tau can be performed using tau-PET (PET: positron emission tomography). Tau-PET binds to insoluble neurofibrillary tangles, another core pathological feature of AD. Six stages that characterize tau pathology have been established through post-mortem studies1,2 and PET brain imaging.3 This illustration represents the stages of tau pathology measured by PET. Early stages are often accompanied by mild memory dysfunction; middle stages are accompanied by mild cognitive impairment; later stages are observed in individuals with AD dementia.

The figure is reprinted from Therriault J, et al. Nat Aging 2022;2(6):565–535. The content is licensed under a Creative Commons Attribution 4.0 International License. https://creativecommons.org/licenses/by/4.0/

file_download Download in HQ

Related content

Article cover image showing blood samples and a hand description Article
Fluid biomarkers in Alzheimer’s disease: from detecting the pathology to understanding when it causes symptoms

Advances in blood biomarkers are transforming the diagnosis and prognosis of Alzheimer’s disease, helping to assess pathology, disease progression, and co-existing pathologies.

13.10.2026 Alzheimer’s Disease
image Image Diagram showing current and potential applications of blood-based biomarkers across the Alzheimer’s disease pathway
Current and potential applications for fluid biomarkers

Overview of how blood-based biomarkers may support screening, diagnosis, staging, prognosis, and treatment decisions across the Alzheimer’s disease continuum.

13.10.2026 Alzheimer’s Disease
image Image Flowchart illustrating a plasma biomarker testing protocol for symptomatic Alzheimer’s disease
A two-step blood-based algorithm

Overview of a plasma biomarker testing pathway for symptomatic Alzheimer’s disease, using p-tau217 and eMTBR-tau243 to guide diagnostic assessment and identify underlying pathology.

13.10.2026 Alzheimer’s Disease