The study transforms ~5,000 T1-weighted OASIS-1-based MRI images (176×208 px, four dementia stages) into brain graphs via a Brightness Distance Matrix and thresholding, computes six distance-based topological indices (Wiener, Szeged, Graovac–Ghorbani, PI, Mostar, NGG), normalizes them with a Watts–Strogatz small-world model, and feeds them to four classifiers .
The optimized 4-hidden-layer neural network achieved fold-wise accuracies of 88.4–90.3% (mean 89.45%, AUC 0.9766–0.9821, mean 0.9788) . Benchmarking places this below raw-image deep-learning baselines on the same data family (ResNet-50 96.7%, GoogleNet 97.54%) but above traditional SIFT+SURF SVM pipelines (~86%) — the trade-off being interpretability and privacy compatibility rather than raw accuracy.
Strengths. The framework is transparent (six scalar indices), open-source (GitHub code released), and the WS-model normalization with a systematic ablation over rewiring probability p and degree δ is a genuine methodological contribution. Privacy claims are logically grounded since only numeric indices leave the source site.
Concerns. (1) The dataset is a single Kaggle mirror of OASIS-1; no independent external validation. (2) Class imbalance was handled with SMOTE on training data only — reasonable, but synthetic samples can inflate minority-class performance. (3) The claimed federated-learning compatibility was not experimentally demonstrated — it is forward-looking, as the authors themselves acknowledge in limitations . (4) Table 1 differences across AD stages are extremely small (clustering coefficient C: non-demented 0.8035 vs moderate 0.7997) with no inferential statistics reported, so the biological separability of stages via these indices alone is not established. (5) Pixel-level graphs are not anatomical connectomes; the 'brain network' framing risks over-interpretation, since BDM adjacency reflects brightness similarity, not neural connectivity.
Context. Deep-learning surveys repeatedly identify dataset heterogeneity, interpretability, and cross-center generalization as the field's core challenges ; this paper addresses interpretability and privacy explicitly, but generalization remains untested.
What would change the verdict: replication on independent multi-site cohorts; ablations showing WS normalization (vs raw indices) actually improves classification; statistical testing of stage-wise index differences; and a demonstrated federated-learning experiment.
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