We explore several oversampling techniques for an imbalanced multi-label classification problem, a setting often encountered when developing models for Computer-Aided Diagnosis (CADx) systems. While most CADx systems aim to optimize classifiers for overall accuracy without considering the relative distribution of each class, we look into using synthetic sampling to increase per-class performance when predicting the degree of malignancy. Using low-level image features and a random forest classifier, we show that using synthetic oversampling techniques increases the sensitivity of the minority classes by an average of 7.22% points, with as much as a 19.88% point increase in sensitivity for a particular minority class. Furthermore, the analysis of low-level image feature distributions for the synthetic nodules reveals that these nodules can provide insights on how to preprocess image data for better classification performance or how to supplement the original datasets when more data acquisition is feasible.

本文探讨了几种多标签不平衡分类问题中的过采样技术，证明了通过使用合成采样技术，可以提高恶性程度预测的每个类的性能敏感性，寻找合适的低层次图像特征和随机森林分类器对数据集进行分类，可以对多标签不平衡分类问题提供信息和指导。

多类恶性预测的合成采样