L-FUSION: Laplacian Fetal Ultrasound Segmentation & Uncertainty Estimation
This work addresses the challenge of reliable fetal ultrasound analysis for clinical settings, offering a scalable solution for early detection of developmental anomalies, though it appears incremental as it builds on existing methods like Stochastic Segmentation Networks and Laplace approximations.
The paper tackled the problem of accurate segmentation and uncertainty estimation in fetal ultrasound images, which is complicated by operator dependency and technical limitations, by proposing L-FUSION, a framework that integrates uncertainty quantification and foundation models, achieving superior segmentation accuracy and consistent uncertainty quantification across multiple datasets.
Accurate analysis of prenatal ultrasound (US) is essential for early detection of developmental anomalies. However, operator dependency and technical limitations (e.g. intrinsic artefacts and effects, setting errors) can complicate image interpretation and the assessment of diagnostic uncertainty. We present L-FUSION (Laplacian Fetal US Segmentation with Integrated FoundatiON models), a framework that integrates uncertainty quantification through unsupervised, normative learning and large-scale foundation models for robust segmentation of fetal structures in normal and pathological scans. We propose to utilise the aleatoric logit distributions of Stochastic Segmentation Networks and Laplace approximations with fast Hessian estimations to estimate epistemic uncertainty only from the segmentation head. This enables us to achieve reliable abnormality quantification for instant diagnostic feedback. Combined with an integrated Dropout component, L-FUSION enables reliable differentiation of lesions from normal fetal anatomy with enhanced uncertainty maps and segmentation counterfactuals in US imaging. It improves epistemic and aleatoric uncertainty interpretation and removes the need for manual disease-labelling. Evaluations across multiple datasets show that L-FUSION achieves superior segmentation accuracy and consistent uncertainty quantification, supporting on-site decision-making and offering a scalable solution for advancing fetal ultrasound analysis in clinical settings.