What is T+? A Gordian Knot of Tracers, Thresholds & Topographies.

In this review we examine, in the context of the AT(N) framework, the available evidence as well as the potential alternatives on how to establish tau-positivity (T+) for multiple tau imaging tracers in order to come to a consensus for "normal" and "abnormal" tau imaging values that can be universally implemented in clinical research and therapeutic trials.