Evidence map›Paper›PMID 41830758›Full record

ArticleThe journal of prevention of Alzheimer's disease2026

Amyloid spatial extent with florbetapir-PET for early detection of preclinical Alzheimer's disease.

Emma G Thibault, Grace Del Carmen Montenegro, J Alex Becker, Julie C Price, Brian C Healy, Bernard J Hanseeuw, Rachel F Buckley, Heidi I L Jacobs, Michael J Properzi, Reisa A Sperling and 2 more

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In one paragraph

Article in The journal of prevention of Alzheimer's disease, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

  1. Article
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

12 authors.

Emma G ThibaultDepartment of Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Boston, MA, 02114, USA.
Grace Del Carmen MontenegroDepartment of Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Boston, MA, 02114, USA.
J Alex BeckerDepartment of Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Boston, MA, 02114, USA.
Julie C PriceDepartment of Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Boston, MA, 02114, USA.
Brian C HealyDepartment of Neurology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Boston, MA, 02114 USA; Biostatistics Center, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St Boston, MA, 02114, USA.
Bernard J HanseeuwDepartment of Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Boston, MA, 02114, USA; Department of Neurology, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Av. Hippocrate 10, 1200 Bruxelles, Belgium.
Rachel F BuckleyDepartment of Neurology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Boston, MA, 02114 USA; Melbourne School of Psychological Sciences, University of Melbourne, Melbourne VIC 3052, Australia; CenterCenter for Alzheimer Research and Treatment, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, 221 Longwood Avenue Boston, MA, 02115, USA.
Heidi I L JacobsDepartment of Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Boston, MA, 02114, USA.
Michael J ProperziDepartment of Neurology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Boston, MA, 02114 USA.
Reisa A SperlingDepartment of Neurology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Boston, MA, 02114 USA; Melbourne School of Psychological Sciences, University of Melbourne, Melbourne VIC 3052, Australia; CenterCenter for Alzheimer Research and Treatment, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, 221 Longwood Avenue Boston, MA, 02115, USA.
Keith A JohnsonDepartment of Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Boston, MA, 02114, USA; Department of Neurology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Boston, MA, 02114 USA; CenterCenter for Alzheimer Research and Treatment, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, 221 Longwood Avenue Boston, MA, 02115, USA. Electronic address: kjohnson@mgh.harvard.edu.
Michelle E FarrellDepartment of Neurology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Boston, MA, 02114 USA. Electronic address: mfarrell13@mgh.harvard.edu.

Funding

Optimizing PET spatial extent measures to detect the earliest amyloid-beta and tau accumulation and associated cognitive decline in preclinical Alzheimer's diseaseK01AG083062 · NIA · MASSACHUSETTS GENERAL HOSPITAL · PI Michelle Elizabeth Farrell · 2023 to 2026
$514k
NIA NIH HHS K01 AG083062
6 · The paper itself

Abstract

backgroundPrevention of Alzheimer's disease (AD) requires biomarkers sensitive to the earliest amyloid-β (Aβ) deposits.

objectivesTo characterize performance of a recently-developed Aβ-PET spatial extent metric (EXT) for early Aβ detection using

designLongitudinal study with up to 5.5 years of PET, plasma and cognitive measures.

settingThe Anti-Amyloid Treatment in Asymptomatic Alzheimer's disease (A4) Study and its companion screen-fail study Longitudinal Evaluation of Amyloid and Neurodegeneration Risk (LEARN) conducted across 67 international sites.

participants1118 cognitively unimpaired older adults from the A4 placebo arm and LEARN. MEASUREMENTS: EXT (% of neocortex above region-specific thresholds), global Aβ SUVR, plasma pTau217, medial temporal (MTL) and temporal neocortical (nTEMP) tau-PET SUVR, and Preclinical Alzheimer Cognitive Composite (PACC).

resultsEXT showed high cross-sectional reliability and longitudinal stability. Using EXT reclassified 21.4% of SUVR-participants from Aβ- to Aβ+ and predicted who would progress to SUVR+ 5.5 years later with 83% sensitivity and 94% specificity. In SUVR- individuals, higher pTau217 associated with greater SUVR only within EXT+ individuals. Baseline EXT outperformed SUVR in predicting MTL tau proliferation. For neocortical tau SUVR and PACC change, EXT was the better predictor in earlier Aβ stages (while Aβ spread) while SUVR was superior later (after Aβ was widespread).

conclusionsEXT is a robust, generalizable PET metric that detects Aβ before global positivity and early Aβ-related changes in tau and cognition, supporting its relevance for trial enrichment and early therapeutic monitoring in AD prevention trials.

Indexed as

Alzheimer DiseaseAmyloid beta-PeptidesAniline CompoundsBrainEthylene GlycolsPositron-Emission TomographyAgedBiomarkersEarly DiagnosisFemaleHumansLongitudinal StudiesMaleProdromal SymptomsReproducibility of Resultstau ProteinsAmyloid beta-PeptidesAniline CompoundsBiomarkersEthylene Glycolsflorbetapirtau ProteinsAmyloidAmyloid stagingEarly detectionPETPreclinical Alzheimer’s diseasepTau217

Identifiers

PMID41830758
PMCPMC12999308

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.