title: High-Throughput Classification of Radiographs Using Deep Convolutional Neural Networks.
abstract: The study aimed to determine if computer vision techniques rooted in deep learning can use a small set of radiographs to perform clinically relevant image classification with high fidelity. One thousand eight hundred eighty-five chest radiographs on 909 patients obtained between January 2013 and July 2015 at our institution were retrieved and anonymized. The source images were manually annotated as frontal or lateral and randomly divided into training, validation, and test sets. Training and validation sets were augmented to over 150,000 images using standard image manipulations. We then pre-trained a series of deep convolutional networks based on the open-source GoogLeNet with various transformations of the open-source ImageNet (non-radiology) images. These trained networks were then fine-tuned using the original and augmented radiology images. The model with highest validation accuracy was applied to our institutional test set and a publicly available set. Accuracy was assessed by using the Youden Index to set a binary cutoff for frontal or lateral classification. This retrospective study was IRB approved prior to initiation. A network pre-trained on 1.2 million greyscale ImageNet images and fine-tuned on augmented radiographs was chosen. The binary classification method correctly classified 100 % (95 % CI 99.73-100 %) of both our test set and the publicly available images. Classification was rapid, at 38 images per second. A deep convolutional neural network created using non-radiological images, and an augmented set of radiographs is effective in highly accurate classification of chest radiograph view type and is a feasible, rapid method for high-throughput annotation.
authors.affiliation: Department of Medicine, Division of Hospital Medicine, University of California, San Francisco, 533 Parnassus Ave., Suite 127a, San Francisco, CA, 94143-0131, USA. Alvin.rajkomar@ucsf.edu.|Center for Digital Health Innovation, University of California, San Francisco, San Francisco, CA, USA. Alvin.rajkomar@ucsf.edu.
authors.forename: Alvin
authors.initials: A
authors.lastname: Rajkomar
authors.affiliation: Center for Digital Health Innovation, University of California, San Francisco, San Francisco, CA, USA.
authors.forename: Sneha
authors.initials: S
authors.lastname: Lingam
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, USA.
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Taylor
authors.affiliation: Center for Digital Health Innovation, University of California, San Francisco, San Francisco, CA, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Blum
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, USA.
authors.forename: John
authors.initials: J
authors.lastname: Mongan
mesh_terms: D006801:Humans; D016571:Neural Networks, Computer; D011859:Radiography / Q000145:classification; D013902:Radiography, Thoracic / Q000145:classification* / Q000706:statistics & numerical data; D011897:Random Allocation; D012189:Retrospective Studies
keywords: Artificial neural networks; Chest radiographs; Computer vision; Convolutional neural network; Deep learning; Machine learning; Radiography