Rajaraman Sivaramakrishnan, Antani Sameer K
Lister Hill National Center for Biomedical Communications, National Library of Medicine, 8600 Rockville Pike, Bethesda, MD 20894 USA.
IEEE Access. 2020;8:27318-27326. doi: 10.1109/access.2020.2971257. Epub 2020 Feb 3.
The proposed study evaluates the efficacy of knowledge transfer gained through an ensemble of modality-specific deep learning models toward improving the state-of-the-art in Tuberculosis (TB) detection. A custom convolutional neural network (CNN) and selected popular pretrained CNNs are trained to learn modality-specific features from large-scale publicly available chest x-ray (CXR) collections including (i) RSNA dataset (normal = 8851, abnormal = 17833), (ii) Pediatric pneumonia dataset (normal = 1583, abnormal = 4273), and (iii) Indiana dataset (normal = 1726, abnormal = 2378). The knowledge acquired through modality-specific learning is transferred and fine-tuned for TB detection on the publicly available Shenzhen CXR collection (normal = 326, abnormal =336). The predictions of the best performing models are combined using different ensemble methods to demonstrate improved performance over any individual constituent model in classifying TB-infected and normal CXRs. The models are evaluated through cross-validation (n = 5) at the patient-level with an aim to prevent overfitting, improve robustness and generalization. It is observed that a stacked ensemble of the top-3 retrained models demonstrates promising performance (accuracy: 0.941; 95% confidence interval (CI): [0.899, 0.985], area under the curve (AUC): 0.995; 95% CI: [0.945, 1.00]). One-way ANOVA analyses show there are no statistically significant differences in accuracy ( = .759) and AUC ( = .831) among the ensemble methods. Knowledge transferred through modality-specific learning of relevant features helped improve the classification. The ensemble model resulted in reduced prediction variance and sensitivity to training data fluctuations. Results from their combined use are superior to the state-of-the-art.
拟议的研究评估了通过一组特定模态深度学习模型获得的知识转移对改进结核病(TB)检测的当前技术水平的效果。训练了一个定制的卷积神经网络(CNN)和选定的流行预训练CNN,以从大规模公开可用的胸部X光(CXR)数据集中学习特定模态特征,这些数据集包括:(i)RSNA数据集(正常 = 8851,异常 = 17833),(ii)儿科肺炎数据集(正常 = 1583,异常 = 4273),以及(iii)印第安纳数据集(正常 = 1726,异常 = 2378)。通过特定模态学习获得的知识被转移并在公开可用的深圳CXR数据集(正常 = 326,异常 = 336)上针对TB检测进行微调。使用不同的集成方法组合表现最佳的模型的预测结果,以证明在对TB感染和正常CXR进行分类时,其性能优于任何单个组成模型。通过在患者层面进行交叉验证(n = 5)来评估模型,目的是防止过拟合、提高稳健性和泛化能力。观察到前3个重新训练模型的堆叠集成表现出有前景的性能(准确率:0.941;95%置信区间(CI):[0.899, 0.985],曲线下面积(AUC):0.995;95% CI:[0.945, 1.00])。单向方差分析表明,集成方法之间在准确率( = 0.759)和AUC( = 0.831)方面没有统计学上的显著差异。通过对相关特征进行特定模态学习转移的知识有助于改进分类。集成模型降低了预测方差以及对训练数据波动的敏感性。它们组合使用的结果优于当前技术水平。