Quantifying Radiographic Knee Osteoarthritis Severity using Deep Convolutional Neural Networks
This work addresses the need for more accurate automated assessment of knee osteoarthritis severity for clinical applications, representing an incremental advance.
The paper tackled the problem of automatically quantifying knee osteoarthritis severity from radiographs by using deep convolutional neural networks, achieving a sizable improvement over the state-of-the-art on the Osteoarthritis Initiative dataset.
This paper proposes a new approach to automatically quantify the severity of knee osteoarthritis (OA) from radiographs using deep convolutional neural networks (CNN). Clinically, knee OA severity is assessed using Kellgren \& Lawrence (KL) grades, a five point scale. Previous work on automatically predicting KL grades from radiograph images were based on training shallow classifiers using a variety of hand engineered features. We demonstrate that classification accuracy can be significantly improved using deep convolutional neural network models pre-trained on ImageNet and fine-tuned on knee OA images. Furthermore, we argue that it is more appropriate to assess the accuracy of automatic knee OA severity predictions using a continuous distance-based evaluation metric like mean squared error than it is to use classification accuracy. This leads to the formulation of the prediction of KL grades as a regression problem and further improves accuracy. Results on a dataset of X-ray images and KL grades from the Osteoarthritis Initiative (OAI) show a sizable improvement over the current state-of-the-art.