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Amyloid PET Quantitation and Centiloid Thresholds in the Diagnosis of Alzheimer Disease: An Individual Participant Data Meta-Analysis
Ganna Blazhenets, David N. Soleimani‐Meigooni, Konstantinos Chiotis, Isabel E. Allen, Gil D. Rabinovici, Renaud La Joie, Meta-Centiloid Study Group, Liana G. Apostolova et al.. Apollo (University of Cambridge), 2026-07-13
Topic: Amyloid, tau and blood-test diagnosis
This meta-analysis included cross-sectional amyloid PET scans acquired with 5 radiotracers from 49 227 participants across 53 studies from 15 countries (mean age, 71 years; 54% female, 62% cognitively impaired). The data-driven GMM approach identified a bimodal distribution in 51 studies (n = 48 786), resulting in a single cutoff for positivity of 18 Centiloids (95% CI,16-19; I2 = 97%). The double-cutoff approach revealed high confidence for interpreting scans as negative when Centiloid values were lower than 11 (95% CI, 9-13; I2 = 95%) and interpreting scans as positive if Centiloid values were higher than 26 (95% CI, 24-28; I2 = 95%). In analyses of correspondence with binary (positive or negative) visual reads of amyloid PET scans (n = 35 045; 36 studies), Centiloids were highly predictive of visual positivity (Cohen κ, 0.86; 95% CI, 0.83-0.89; I2 = 96%) with a cutoff of 27 Centiloids (95% CI, 24-30; I2 = 80%). CONCLUSIONS AND RELEVANCE: In this individual participant data meta-analysis, positivity cutoffs converged around 18 Centiloids (data-driven) and 27 Centiloids (visual reads). Findings from a double-cutoff analysis suggest that scans in the 11 to 26 Centiloid range should be interpreted with caution depending on the context of use.
Key findings
- This meta-analysis included cross-sectional amyloid PET scans acquired with 5 radiotracers from 49 227 participants across 53 studies from 15 countries (mean age, 71 years; 54% female, 62% cognitively impaired).
- The data-driven GMM approach identified a bimodal distribution in 51 studies (n = 48 786), resulting in a single cutoff for positivity of 18 Centiloids (95% CI,16-19; I2 = 97%).
- The double-cutoff approach revealed high confidence for interpreting scans as negative when Centiloid values were lower than 11 (95% CI, 9-13; I2 = 95%) and interpreting scans as positive if Centiloid values were higher than 26 (95% CI, 24-28; I2 = 95%).
- In analyses of correspondence with binary (positive or negative) visual reads of amyloid PET scans (n = 35 045; 36 studies), Centiloids were highly predictive of visual positivity (Cohen κ, 0.86; 95% CI, 0.83-0.89; I2 = 96%) with a cutoff of 27 Centiloids (95% CI, 24-30; I2 = 80%).
- CONCLUSIONS AND RELEVANCE: In this individual participant data meta-analysis, positivity cutoffs converged around 18 Centiloids (data-driven) and 27 Centiloids (visual reads).
Why it matters
This large meta-analysis of amyloid PET scans from 49,227 participants found that positivity cutoffs converged around 18 Centiloids using a data-driven approach and 27 Centiloids for visual reads. The authors advise that scans in the 11 to 26 Centiloid range should be interpreted with caution depending on the context.
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Study details
- Study designmeta-analysis
- Participants48
- Evidence strengthHigh
How this study scored 52/100
Published in a peer-reviewed journal, and it is a meta-analysis pooling many studies. Scored zero for effect reported because the record does not state it. We have no data on journal's citation record and institution's track record, so those were left out: it earned 48 of the 93 points we could judge it on, which is 52 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Apollo (University of Cambridge)) |
| Journal's citation record | — / 4 | No journal record from OpenAlex — left out of this score |
| Study design | 12 / 12 | A meta-analysis pooling many studies |
| Strength of evidence | 5 / 5 | Rated “high” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 5 / 5 | 2026 — within 1 year(s) of the newest study here |
| Sample size | 1 / 4 | 48 participants |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 3 / 3 | Studied in people (participant count stated) |
| Randomised / blinded | 0 / 2 | A review of other studies — randomisation is not credited here |
| Times cited | 0 / 7 | Cited 0 times (OpenAlex, 2026-10-10) |
| Citations per year | 0 / 5 | 0.0 citations a year over 2 year(s) since 2026 |
| Impact for its field and year | 0 / 6 | Cited 0.0× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 0 / 6 | No other study in this library cites it |
| Still being cited | 0 / 4 | Cited 0 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 2 / 4 | Last-listed author Heather M. Snyder: h-index 36 (OpenAlex, whole career) |
| Institution's track record | — / 3 | No institution listed in OpenAlex — left out of this score |
| Multi-centre collaboration | 0 / 3 | OpenAlex lists 0 institution(s) in 0 countries — scores zero (affiliation lists can be incomplete) |
| Indexed in PubMed | 1 / 2 | Not in PubMed, but has a DOI |
| Free to read | 2 / 2 | Free to read |
| Points | 48 / 93 | Scored on 18 of 20 parts. We have no data for the rest, so they are left out: 48 of the 93 points we could judge it on is 52 out of 100. |
| Total | 52 / 100 | — |
What each of these 20 components measures, and what this score is not →
Read the original
Full text: free to read — OpenAlex lists this copy as free to read: the link above (checked 6 Feb 1020).
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. The record's author list ends in “et al.”, so not every author is named. Check the citation against the original before you use it.
APA 7th
Blazhenets, G., Soleimani‐Meigooni, D. N., Chiotis, K., Allen, I. E., Rabinovici, G. D., La Joie, R., et al. (2026). Amyloid PET Quantitation and Centiloid Thresholds in the Diagnosis of Alzheimer Disease: An Individual Participant Data Meta-Analysis. Apollo (University of Cambridge). https://doi.org/10.17863/cam.132978
Vancouver
Blazhenets G, Soleimani‐Meigooni DN, Chiotis K, Allen IE, Rabinovici GD, La Joie R, et al. Amyloid PET Quantitation and Centiloid Thresholds in the Diagnosis of Alzheimer Disease: An Individual Participant Data Meta-Analysis. Apollo (University of Cambridge). 2026. doi:10.17863/cam.132978.
BibTeX
@article{blazhenets2026-9fe17487,
author = {Blazhenets, Ganna and Soleimani‐Meigooni, David N. and Chiotis, Konstantinos and Allen, Isabel E. and Rabinovici, Gil D. and La Joie, Renaud and {Meta-Centiloid Study Group} and Apostolova, Liana G. and others},
title = {{Amyloid PET Quantitation and Centiloid Thresholds in the Diagnosis of Alzheimer Disease: An Individual Participant Data Meta-Analysis}},
journal = {Apollo (University of Cambridge)},
year = {2026},
doi = {10.17863/cam.132978},
url = {https://doi.org/10.17863/cam.132978}
}
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