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Using serial registered brain magnetic resonance imaging to measure disease progression in Alzheimer disease: power calculations and estimates of sample size to detect treatment effects
Fox NC, Cousens S, Scahill R, Harvey RJ, Rossor MN.. Archives of neurology, 2000-03-01
Topic: Amyloid, tau and blood-test diagnosis
Objective To evaluate the rate of brain atrophy calculated from serial magnetic resonance imaging (MRI) registration as a surrogate marker of disease progression for use in clinical trials in Alzheimer disease (AD). Methods Eighteen patients with mild to moderate AD and 18 age-matched normal controls underwent 2 MRI brain scans separated by a 12-month interval. Each individual's later scan was registered to their first scan, and the volume of cerebral tissue loss calculated directly from the registered and subtracted MRI scan pairs. The mean and SD of the rate of brain volume changes were used to estimate the sample sizes that would be needed in a clinical trial with a drug anticipated to modify disease progression by varying degrees. Comparable sample size estimates were performed with data for other methods of monitoring rates of brain atrophy, extracted from published papers. Results The mean (SD) rate of brain atrophy for the patients with AD was 2.37% (1.11%) per year, while in the control group it was 0.41% (0.47%) per year. Based on these figures, to have 90% power to detect a drug effect equivalent to a 20% reduction in the rate of atrophy, 207 patients would be needed in each treatment arm. This assumes a 1-year placebo-controlled trial with a 10% patient dropout rate, and that 10% of scan pairs are unusable. Conclusion Registration of serial MRI volume images provides a powerful method of quantification of brain atrophy that can be used to monitor progression of AD in clinical trials.
Key findings
- Results The mean (SD) rate of brain atrophy for the patients with AD was 2.37% (1.11%) per year, while in the control group it was 0.41% (0.47%) per year.
Why it matters
Serial MRI showed that patients with mild to moderate Alzheimer's disease lost brain volume at about 2.37% per year, compared with 0.41% per year in controls, and the authors calculated sample sizes needed to detect a treatment effect. This is a methodological study about measuring progression in trials, not a treatment or cure.
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Study details
- Participants207
- Effect size2.37%; 1.11%; 0.41%
- Evidence strengthLow
How this study scored 53/100
Published in a peer-reviewed journal. Scored zero for study design and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Archives of neurology) |
| Journal's citation record | 3 / 4 | Archives of Neurology: journal h-index 353 (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 | 1 / 5 | Rated “low” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 1 / 5 | 2000 — older than 20 years, still counted |
| Sample size | 2 / 4 | 207 participants |
| Effect reported | 2 / 3 | Effect reported as a number, without an interval or test |
| Studied in people | 3 / 3 | Studied in people (participant count stated) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 6 / 7 | Cited 360 times (OpenAlex, 2026-10-10) |
| Citations per year | 3 / 5 | 12.9 citations a year over 28 year(s) since 2000 |
| Impact for its field and year | 4 / 6 | Cited 13.1× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 3 / 6 | Cited by 29 other studies in this library |
| Still being cited | 1 / 4 | Cited 8 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 4 / 4 | Last-listed author Martin N. Rossor: h-index 135 (OpenAlex, whole career) |
| Institution's track record | 1 / 3 | UCL Queen Square Institute of Neurology: institution h-index 875 (OpenAlex) |
| Multi-centre collaboration | 0 / 3 | OpenAlex lists 1 institution(s) in 1 country — scores zero (affiliation lists can be incomplete) |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 10714659) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 53 / 100 | — |
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Read the original
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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. Check the citation against the original before you use it.
APA 7th
Fox, N. C., Cousens, S., Scahill, R., Harvey, R. J., & Rossor, M. N. (2000). Using serial registered brain magnetic resonance imaging to measure disease progression in Alzheimer disease: power calculations and estimates of sample size to detect treatment effects. Archives of neurology. https://doi.org/10.1001/archneur.57.3.339
Vancouver
Fox NC, Cousens S, Scahill R, Harvey RJ, Rossor MN. Using serial registered brain magnetic resonance imaging to measure disease progression in Alzheimer disease: power calculations and estimates of sample size to detect treatment effects. Archives of neurology. 2000. doi:10.1001/archneur.57.3.339. PMID: 10714659.
BibTeX
@article{fox2000-10714659,
author = {Fox, N. C. and Cousens, S. and Scahill, R. and Harvey, R. J. and Rossor, M. N.},
title = {{Using serial registered brain magnetic resonance imaging to measure disease progression in Alzheimer disease: power calculations and estimates of sample size to detect treatment effects}},
journal = {Archives of neurology},
year = {2000},
doi = {10.1001/archneur.57.3.339},
pmid = {10714659},
url = {https://doi.org/10.1001/archneur.57.3.339}
}
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