TABLE 1.

AT(N) biomarker grouping of the NIA-AA framework.

Biomarker class	CSF marker	Imaging marker
Amyloid (A)	CSF Aβ42 or Aβ42:Aβ40 ratio	Amyloid PET
Tau (T)	CSF p-tau	Tau PET
Neurodegeneration (N)	CSF t-tau	Anatomic MRI; FDG-PET

Adapted from Jack et al. (2016). NIH, National Institute on Aging; NIA-AA, Alzheimer’s Association; CSF, cerebrospinal fluid; Aβ, amyloid-β; p-tau, phosphorylated tau; t-tau, total tau; PET, positron emission tomography; MRI, magnetic resonance imaging; FDG, fluorine-based tracers.