{"about":{"site":"https://codewithpapers.app","non_affiliation":"Code with Papers and Syntology are not affiliated with, endorsed by, or sponsored by Papers with Code, Meta, or the pwc-archive mirror.","licence":"CC BY-SA 4.0","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","attribution":"https://codewithpapers.app/attribution","modified":"archive material modified by Syntology; see the attribution page"},"url":"/paper/enhancing-out-of-distribution-detection-in-1","title":"Enhancing Out-of-Distribution Detection in Medical Imaging with Normalizing Flows","arxiv_id":"2502.11638","date":"2025-02-17","proceeding":null,"authors":["Dariush Lotfi","Mohammad-Ali Nikouei Mahani","Mohamad Koohi-Moghadam","Kyongtae Ty Bae"],"abstract":"Out-of-distribution (OOD) detection is crucial in AI-driven medical imaging to ensure reliability and safety by identifying inputs outside a model's training distribution. Existing methods often require retraining or modifications to pre-trained models, which is impractical for clinical applications. This study introduces a post-hoc normalizing flow-based approach that seamlessly integrates with pre-trained models. By leveraging normalizing flows, it estimates the likelihood of feature vectors extracted from pre-trained models, capturing semantically meaningful representations without relying on pixel-level statistics. The method was evaluated using the MedMNIST benchmark and a newly curated MedOOD dataset simulating clinically relevant distributional shifts. Performance was measured using standard OOD detection metrics (e.g., AUROC, FPR@95, AUPR_IN, AUPR_OUT), with statistical analyses comparing it against ten baseline methods. On MedMNIST, the proposed model achieved an AUROC of 93.80%, outperforming state-of-the-art methods. On MedOOD, it achieved an AUROC of 84.61%, demonstrating superior performance against other methods. Its post-hoc nature ensures compatibility with existing clinical workflows, addressing the limitations of previous approaches. The model and code to build OOD datasets are available at https://github.com/dlotfi/MedOODFlow.","url_abs":"https://arxiv.org/abs/2502.11638v1","url_pdf":"https://arxiv.org/pdf/2502.11638v1.pdf","source":{"archive":"pwc-archive (Hugging Face), CC BY-SA 4.0","snapshot":"2025-07-28","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","row_kind":"abstracts"},"code_links":[{"paper_slug":"enhancing-out-of-distribution-detection-in-1","repo_url":"https://github.com/dlotfi/medoodflow","is_official":1,"mentioned_in_paper":1,"mentioned_in_github":0,"framework":"pytorch","reach":null}],"tasks":[{"task_slug":"ood-detection","task_name":"Out of Distribution (OOD) Detection"},{"task_slug":"out-of-distribution-detection","task_name":"Out-of-Distribution Detection"}],"methods":[],"datasets_introduced":[],"methods_introduced":[],"results":[],"syntology":{"syntology_url":null,"atlas_url":null,"mcp":null,"developers":"https://syntology.ai/developers"},"arxiv_metadata":null,"syntology_extracted_results":null}