Tau PET Tracers — Binding Aggregated Tau Paired Helical Filaments
Placeholder: tau PET tracers selectively bind aggregated tau, not amyloid.
- 18F: Tracer class (Placeholder tracer family note)
- PHF-tau: Binding target (Placeholder target description)
- ~110 min: Half-life (Placeholder isotope property)
- Low–mod: Off-target binding (Placeholder specificity note)
Tracer chemistry and binding placeholder
Placeholder: describes tracer chemical structure and PHF affinity.
Placeholder: off-target binding to MAO-B and other sites.
Placeholder: pharmacokinetics and brain clearance timeline.
Regional Tracer Uptake Following the Braak Staging Sequence
Placeholder: tau spreads through the brain in a stereotyped regional sequence.
- Entorhinal: Braak I–II (Placeholder region note)
- Limbic: Braak III–IV (Placeholder region note)
- Neocortex: Braak V–VI (Placeholder region note)
- 6: Stages defined (Placeholder Braak scale note)
Regional progression placeholder
Placeholder: describes entorhinal-to-neocortical spread pattern.
Placeholder: correlation between PET signal and postmortem Braak stage.
Quantifying Regional Tau Burden with SUVR Metrics
Placeholder: SUVR quantifies tracer uptake relative to a reference region.
- Cerebellum: Reference region (Placeholder reference note)
- 1.0–3.0: SUVR range (Placeholder illustrative range)
- ~1.3: Positivity cutoff (Placeholder threshold note)
- 11: ROI count (Placeholder region atlas note)
SUVR quantification placeholder
Placeholder: explains SUVR calculation and composite ROI scoring.
Placeholder: partial volume correction considerations.
Assigning a Disease Stage from the Observed PET Pattern
Placeholder: composite regional pattern maps onto a Braak-equivalent stage.
- Pattern match: Staging method (Placeholder algorithm note)
- Moderate–high: Concordance vs autopsy (Placeholder validation note)
- Limited: Early-stage sensitivity (Placeholder caveat)
- Stage I–VI: Output (Placeholder output format)
Automated staging placeholder
Placeholder: describes automated Braak-stage classification from PET.
Placeholder: sources of staging uncertainty and edge cases.
Using Tau PET Staging for Treatment and Trial Decisions
Placeholder: staging informs eligibility, monitoring, and treatment choices.
- Yes: Trial enrollment use (Placeholder eligibility note)
- Longitudinal: Treatment monitoring (Placeholder monitoring note)
- In development: Anti-tau therapies (Placeholder therapy note)
- High: Prognostic value (Placeholder prognosis note)
Clinical decision-making placeholder
Placeholder: describes how stage informs trial and treatment decisions.
Placeholder key insight: staging links imaging pattern to clinical action.