ABSTRACT
Diseases of the optic nerve cause structural changes observable through clinical computed tomography (CT) imaging. Previous work has shown that multi-atlas methods can be used to segment and extract volumetric measurements from the optic nerve, which are associated with visual disability and disease. In this work, we trained a weakly supervised convolutional neural network to learn optic nerve volumes directly, without segmentation. Furthermore, we explored the role of contextual electronic medical record (EMR) information, specifically ICD-9 codes, to improve optic nerve volume estimation. We constructed a merged network to combine data from imaging as well as EMR and demonstrated that context improved volume prediction, with a 15% increase in explained-variance ( R 2). Finally, we compared disease prediction models using volumes learned from multi-atlas, CNN, and contextual-CNN. We observed that the predicted optic nerve volume from merge-CNN had an AUC of 0.74 for classification of disease, as compared to an AUC of 0.54 using the multi-atlas metric. This is the first work to show that a contextually derived volume biomarker is more accurate than volume estimations through multi-atlas or weakly supervised image CNN. These results highlight the potential for image processing improvements by incorporating non-imaging data.
