Mammographic Image Classification System via Active Learning

Training an accurate prediction model for mammographic image classification is usually necessary to require a large number of labeled images. However, the manually acquiring rich and reliable annotations is known to be tedious and time-consuming process, especially for medical image. The advances in machine learning yielded a branch of technique, termed active learning (AL), which has been proposed for solving the problem of the limited training samples and expensive labeling cost, and has resulted in highly successful applications in many pattern recognition tasks such as image processing and speech recognition. In this article, a comparison is provided among the mammographic image classification systems, relying on traditional supervised learning, un-supervised learning and AL, aiming to obtain a system with low labeling cost. The experiments based on digital database for screening mammography demonstrate that the AL is able to minimize the labeling cost of mammographic image without sacrificing the accuracy of final classification system. In addition, some specific characteristics of mammographic image: file information and spatial feature, which are not available to the traditional AL methods, have been found to further decrease the labeling cost. In conclusion, we suggest that the AL is a reasonable alternative to supervised learning for the researchers in the field of medical image classification with limited experimental conditions.