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Concordance between Centiloid Quantification and Visual Interpretation of Amyloid PET Scans across the Alzheimer Disease Continuum
Khalafi M, Hojjati SH, Wang XH, Zhou L, Nordvig AS, Li Y, Butler TA, Razlighi QR et al.. AJNR. American journal of neuroradiology, 2025-09-02
Topic: Amyloid, tau and blood-test diagnosis
Background and purpose Accurate identification of cerebral β-amyloid (Aβ) accumulation is crucial for diagnosing Alzheimer disease (AD) and determining eligibility for anti-Aβ therapies. The Centiloid (CL) scale has emerged as a standardized method to harmonize Aβ PET quantification across different tracers and sites. We aimed to evaluate the concordance between CL quantification and visual interpretation in a cohort of cognitively impaired (CI) and unimpaired (CU) participants who underwent Aβ PET. Materials and methods Two hundred twenty-one participants (mean age 69 ± 12.3 years) were prospectively enrolled in AD studies and underwent 247 Aβ PET scans, including 157 with [ 11 C]-Pittsburgh compound B (PiB) and 90 with [ 18 F]-florbetaben (FBB). Standardized uptake value ratios (SUVRs) were converted to the CL scale following Global Alzheimer's Association Interactive Network guidelines. Percent agreement and κ statistics were used to evaluate the concordance between CL thresholds and visual interpretation in determining Aβ positivity. Results The highest concordance rate for the whole cohort was 93% by using a CL cutoff of 18 (κ coefficient 0.84). Using FBB, the concordance rate was highest by using a CL cutoff of 24 (97%), whereas the concordance rate for PiB peaked at 94% at a CL cutoff of 18. Concordance was higher in negative rather than positive Aβ PET cases, 98% versus 90%. Concordance was slightly higher in CI participants compared with CU (96% versus 93%). Disagreement commonly occurred when focal areas of Aβ positivity were identified on visual interpretation but did not meet the threshold globally by CL quantification. Conclusions Global CL quantification of Aβ PET scans is highly concordant with visual interpretation. Combining both methods may provide a more complete assessment of the extent of Aβ deposition in the brain.
Key findings
- Results The highest concordance rate for the whole cohort was 93% by using a CL cutoff of 18 (κ coefficient 0.84).
- Concordance was higher in negative rather than positive Aβ PET cases, 98% versus 90%.
- Concordance was slightly higher in CI participants compared with CU (96% versus 93%).
Why it matters
In 221 participants, a standardized Centiloid cutoff of 18 agreed with visual reading of amyloid PET scans in 93% of cases, with the best cutoff differing slightly by tracer. This supports harmonizing amyloid PET quantification for diagnosis and eligibility for anti-amyloid therapies, but does not itself treat or prevent disease.
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Study details
- Evidence strengthModerate
How this study scored 43/100
Published in a peer-reviewed journal. Scored zero for study design, sample size, effect reported, studied in people and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (AJNR. American journal of neuroradiology) |
| Journal's citation record | 2 / 4 | American Journal of Neuroradiology: journal h-index 182 (OpenAlex, 2026-10-29) |
| Study design | 0 / 12 | No study design recorded — scores zero, not guessed (not stated in the record — scored 0) |
| Strength of evidence | 3 / 5 | Rated “moderate” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 4 / 5 | 2025 — within 3 year(s) of the newest study here |
| Sample size | 0 / 4 | Participant count not stated — scores zero (not stated in the record — scored 0) |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 0 / 3 | Not stated whether this was studied in people — scores zero (not stated in the record — scored 0) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 2 / 7 | Cited 14 times (OpenAlex, 2026-10-10) |
| Citations per year | 2 / 5 | 4.7 citations a year over 3 year(s) since 2025 |
| Impact for its field and year | 4 / 6 | Cited 8.9× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 1 / 6 | Cited by 1 other studies in this library |
| Still being cited | 1 / 4 | Cited 14 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 2 / 4 | Last-listed author Gloria Chia-Yi Chiang: h-index 36 (OpenAlex, whole career) |
| Institution's track record | 2 / 3 | Cornell University: institution h-index 1,649 (OpenAlex) |
| Multi-centre collaboration | 1 / 3 | OpenAlex lists 3 institution(s) in 1 country |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 40101933) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 43 / 100 | — |
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Read the original
Full text: free to read — PubMed Central lists this copy as free to read: the link above (checked 10 Oct 2026).
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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
Khalafi, M., Hojjati, S. H., Wang, X. H., Zhou, L., Nordvig, A. S., Li, Y., et al. (2025). Concordance between Centiloid Quantification and Visual Interpretation of Amyloid PET Scans across the Alzheimer Disease Continuum. AJNR. American journal of neuroradiology. https://doi.org/10.3174/ajnr.a8743
Vancouver
Khalafi M, Hojjati SH, Wang XH, Zhou L, Nordvig AS, Li Y, et al. Concordance between Centiloid Quantification and Visual Interpretation of Amyloid PET Scans across the Alzheimer Disease Continuum. AJNR. American journal of neuroradiology. 2025. doi:10.3174/ajnr.a8743. PMID: 40101933.
BibTeX
@article{khalafi2025-40101933,
author = {Khalafi, M. and Hojjati, S. H. and Wang, X. H. and Zhou, L. and Nordvig, A. S. and Li, Y. and Butler, T. A. and Razlighi, Q. R. and others},
title = {{Concordance between Centiloid Quantification and Visual Interpretation of Amyloid PET Scans across the Alzheimer Disease Continuum}},
journal = {AJNR. American journal of neuroradiology},
year = {2025},
doi = {10.3174/ajnr.a8743},
pmid = {40101933},
url = {https://doi.org/10.3174/ajnr.a8743}
}
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