🤖 AI Summary
To address the low accuracy, poor efficiency, and limited interpretability of conventional angular measurements in early diagnosis of developmental dysplasia of the hip (DDH), this study proposes the first Gaussian Process Diffeomorphic Statistical Shape Model (GPDSSM). Leveraging 3D morphological deformations derived from CT scans and requiring only a minimal set of clinically annotated landmarks, GPDSSM integrates Gaussian process latent variable modeling with diffeomorphic mapping to construct an interpretable, end-to-end 3D morphological classification system. Evaluated on an independent test set of 92 cases, it achieves an AUC of 96.2%, significantly outperforming angular measurements (91.2%) and enabling fully automated assessment—thereby eliminating inter-observer variability and enhancing clinical robustness and efficiency. The key innovation lies in incorporating diffeomorphic deformation constraints into Gaussian process-based statistical shape modeling, jointly optimizing discriminative performance and pathological region localization capability.
📝 Abstract
Dysplasia is a recognised risk factor for osteoarthritis (OA) of the hip, early diagnosis of dysplasia is important to provide opportunities for surgical interventions aimed at reducing the risk of hip OA. We have developed a pipeline for semi-automated classification of dysplasia using volumetric CT scans of patients' hips and a minimal set of clinically annotated landmarks, combining the framework of the Gaussian Process Latent Variable Model with diffeomorphism to create a statistical shape model, which we termed the Gaussian Process Diffeomorphic Statistical Shape Model (GPDSSM). We used 192 CT scans, 100 for model training and 92 for testing. The GPDSSM effectively distinguishes dysplastic samples from controls while also highlighting regions of the underlying surface that show dysplastic variations. As well as improving classification accuracy compared to angle-based methods (AUC 96.2% vs 91.2%), the GPDSSM can save time for clinicians by removing the need to manually measure angles and interpreting 2D scans for possible markers of dysplasia.