Self-supervised learning leverages the underlying data structure as the source of the supervisory signal without the need for human annotation effort. This approach offers a practical solution to learning with a large amount of biomedical data and limited annotation. Unlike other studies exploiting data via multi-view (e.g., augmented images), this study presents a self-supervised Dual-Loss Adaptive Masked Autoencoder (DAMA) algorithm established from the viewpoint of the information theory. Specifically, our objective function maximizes the mutual information by minimizing the conditional entropy in pixel-level reconstruction and feature-level regression. We further introduce an adaptive mask sampling strategy to maximize mutual information. We conduct extensive experiments on brain cell images to validate the proposed method. DAMA significantly outperforms both state-of-the-art self-supervised and supervised methods on brain cells data and demonstrates competitive result on ImageNet-1k. Code: https://github.com/hula-ai/DAMA
Accurate breast lesion risk estimation can significantly reduce unnecessary biopsies and help doctors decide optimal treatment plans. Most existing computer-aided systems rely solely on mammogram features to classify breast lesions. While this approach is convenient, it does not fully exploit useful information in clinical reports to achieve the optimal performance. Would clinical features significantly improve breast lesion classification compared to using mammograms alone? How to handle missing clinical information caused by variation in medical practice? What is the best way to combine mammograms and clinical features? There is a compelling need for a systematic study to address these fundamental questions. This paper investigates several multimodal deep networks based on feature concatenation, cross-attention, and co-attention to combine mammograms and categorical clinical variables. We show that the proposed architectures significantly increase the lesion classification performance (average area under ROC curves from 0.89 to 0.94). We also evaluate the model when clinical variables are missing.