Interpretable Representation Learning of Cardiac MRI via Attribute Regularization
Maxime Di Folco, Cosmin I. Bercea, Emily Chan, Julia A. Schnabel
TL;DR
Interpreting latent representations in medical imaging is crucial for clinician trust, yet VAEs often produce blurry reconstructions. This work introduces AR-SIVAE, which integrates an attribute regularization loss $\mathcal{L}_{attr}$ into the Soft Introspective VAE framework, with $\alpha=2$, to align latent dimensions with clinically relevant attributes while maintaining sharp generation. Evaluated on UK Biobank cardiac MRI, AR-SIVAE achieves non-blurry reconstructions and improved interpretability of the latent space compared to baselines such as $\beta$-VAE, SIVAE, and Attri-VAE, evidenced by interpretable latent traversals and higher SCC metrics. The approach enables attribute-controlled latent factors suitable for downstream cardiac MRI tasks, though it relies on many hyperparameters and could benefit from extending to non morphometric attributes and downstream classification applications.
Abstract
Interpretability is essential in medical imaging to ensure that clinicians can comprehend and trust artificial intelligence models. Several approaches have been recently considered to encode attributes in the latent space to enhance its interpretability. Notably, attribute regularization aims to encode a set of attributes along the dimensions of a latent representation. However, this approach is based on Variational AutoEncoder and suffers from blurry reconstruction. In this paper, we propose an Attributed-regularized Soft Introspective Variational Autoencoder that combines attribute regularization of the latent space within the framework of an adversarially trained variational autoencoder. We demonstrate on short-axis cardiac Magnetic Resonance images of the UK Biobank the ability of the proposed method to address blurry reconstruction issues of variational autoencoder methods while preserving the latent space interpretability.
