RT Journal Article SR Electronic T1 Weakly supervised classification of aortic valve malformations using unlabeled cardiac MRI sequences JF bioRxiv FD Cold Spring Harbor Laboratory SP 339630 DO 10.1101/339630 A1 Jason A. Fries A1 Paroma Varma A1 Vincent S. Chen A1 Ke Xiao A1 Heliodoro Tejeda A1 Priyanka Saha A1 Jared Dunnmon A1 Henry Chubb A1 Shiraz Maskatia A1 Madalina Fiterau A1 Scott Delp A1 Euan Ashley A1 Christopher RĂ© A1 James R. Priest YR 2019 UL http://biorxiv.org/content/early/2019/05/11/339630.abstract AB Biomedical repositories such as the UK Biobank provide increasing access to prospectively collected cardiac imaging, however these data are unlabeled which creates barriers to their use in supervised machine learning. We develop a weakly supervised deep learning model for classification of aortic valve malformations using up to 4,000 unlabeled cardiac MRI sequences. Instead of requiring highly curated training data, weak supervision relies on noisy heuristics defined by domain experts to programmatically generate large-scale, imperfect training labels. For aortic valve classification, models trained with imperfect labels substantially outperform a supervised model trained on hand-labeled MRIs. In an orthogonal validation experiment using health outcomes data, our model identifies individuals with a 1.8-fold increase in risk of a major adverse cardiac event. This work formalizes a learning baseline for aortic valve classification and outlines a general strategy for using weak supervision to train machine learning models using unlabeled medical images at scale.