Gaussian Process Diffeomorphic Statistical Shape Modelling Outperforms Angle-Based Methods for Assessment of Hip Dysplasia

📅 2025-06-05
📈 Citations: 0
✨ Influential: 0
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🤖 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.

Technology Category

Machine Learning: Learning with ManifoldsSearch and Optimization: Mixed Discrete/Continuous SearchComputer Vision: Diffusion Models for Vision

Application Category

Semantics and Knowledge: Methods, algorithms and applications for the development of semantic models, knowledge graphs and other forms of structured data models with machine-interpretable semanticsUser Modeling, Personalization and Recommendation: On-Device user modeling, personalization, and recommendationGraph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs
📝 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.
Problem

Research questions and friction points this paper is trying to address.

Develops a model to classify hip dysplasia more accurately than angle-based methods
Uses CT scans and landmarks to create a statistical shape model (GPDSSM)
Reduces clinician workload by automating angle measurements and 2D scan analysis
Innovation

Methods, ideas, or system contributions that make the work stand out.

Gaussian Process Diffeomorphic Statistical Shape Model
Volumetric CT scans for dysplasia classification
Combines GPLVM with diffeomorphism framework
A
Allen Paul
Department of Mathematical Sciences, University of Bath, UK
G
George Grammatopoulos
The Ottawa Hospital, Ottawa, Canada
A
Adwaye Rambojun
Department of Mathematical Sciences, University of Bath, UK
N
Neill D. F. Campbell
Department of Computer Science, University of Bath, UK
H
Harinderjit S. Gill
Department of Mechanical Engineering, University of Bath, UK
Tony Shardlow
Tony Shardlow
Department of Mathematical Sciences, University of Bath
Numerical analysisstochastic differential equations