Improving Normative Modeling for Multi-Modal Neuroimaging Data Using Mixture-of-Product-of-Experts Variational Autoencoders

• Published in: Proceedings (International Symposium on Biomedical Imaging) Vol. 2024; pp. 1 - 5
• Main Authors: Kumar, Sayantan, Payne, Philip, Sotiras, Aristeidis
• Format: Conference Proceeding Journal Article
• Language: English
• Published: United States IEEE 01.05.2024
• Subjects: Brain modeling; Data aggregation; Data models; Estimation; mixture-of-product-of-experts; multimodal; Neuroimaging; normative modelling; Pathology; Sociology; variational autoencoders; variational autoencoders; mixture-of-product-of-experts; multimodal; normative modelling
• ISSN: 1945-7928; 1945-8452
• DOI: 10.1109/ISBI56570.2024.10635897

Normative models in neuroimaging learn the brain patterns of healthy population distribution and estimate how disease subjects like Alzheimer's Disease (AD) deviate from the norm. Existing variational autoencoder (VAE)-based normative models using multimodal neuroimaging data aggregate information from multiple modalities by estimating product or averaging of unimodal latent posteriors. This can often lead to uninformative joint latent distributions which affects the estimation of subject-level deviations. In this work, we addressed the prior limitations by adopting the Mixture-of-Product-of-Experts (MoPoE) technique which allows better modelling of the joint latent posterior. Our model labelled subjects as outliers by calculating deviations from the multimodal latent space. Further, we identified which latent dimensions and brain regions were associated with abnormal deviations due to AD pathology.