Diagnostic Accuracy and External Validation of Self-Supervised Learning for Cerebral Micro-Bleed Detection: A Multi-Sequence MRI Trial Using Public Datasets
Abstract
Purpose Cerebral microbleeds (CMBs) are critical imaging biomarkers for small vessel disease, but detection remains challenging due to small lesion size, variable MRI appearance, and annotation burden. This study developed a self-supervised learning (SSL) framework for robust CMB detection across multi-sequence MRI that generalizes to heterogeneous protocols while reducing dependence on labeled data.Materials and Methods An SSL framework (3D ResNet-18 with Barlow Twins loss) was pretrained on 2,450 unlabeled multi-sequence MRI scans (MICCAI 2022, VALDO, UK Biobank), then fine-tuned with only 400 labeled scans using a 3D U-Net for voxel-level detection. Performance was evaluated using ROC-AUC, sensitivity, false positives per scan, lesion-level F1-score, and cross-sequence generalization.Results The SSL framework achieved an AUC of 0.92 (95% CI: 0.90–0.94), sensitivity of 81%, and 1.1 false positives per scan—outperforming fully supervised (AUC 0.84) and semi-supervised (AUC 0.90) baselines. The model maintained robust performance across SWI (AUC 0.93), GRE (AUC 0.90), and 3T scanners (AUC 0.92), with lesion-level F1-scores of 78–84%. SSL pretraining enabled stable detection with as few as 100 labeled scans (AUC 0.90), demonstrating substantial annotation efficiency.Conclusion Self-supervised learning enables robust, generalizable CMB detection across heterogeneous multi-sequence MRI while significantly reducing annotation requirements. The framework's strong cross-sequence generalization supports its potential as a scalable clinical decision-support tool, though prospective validation in independent cohorts remains necessary.
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Citation Information
@article{rameswaripoornimajanardanan2026,
title={Diagnostic Accuracy and External Validation of Self-Supervised Learning for Cerebral Micro-Bleed Detection: A Multi-Sequence MRI Trial Using Public Datasets},
author={Rameswari Poornima Janardanan and Elamir A. Osman and Omer O. Saeed and Mahmoud Eltahir Ali and Omer Gaddoura},
journal={Research Square},
year={2026},
doi={https://doi.org/10.21203/rs.3.rs-9496185/v1}
}
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