Li Feng, Chen Hua, Liu Zheng, Zhang Xue-Dian, Jiang Min-Shan, Wu Zhi-Zheng, Zhou Kai-Qian
School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
Department of Biomedical Engineering, Florida International University, Miami, FL 33174, USA.
Biomed Opt Express. 2019 Nov 11;10(12):6204-6226. doi: 10.1364/BOE.10.006204. eCollection 2019 Dec 1.
Retinal disease classification is a significant problem in computer-aided diagnosis (CAD) for medical applications. This paper is focused on a 4-class classification problem to automatically detect choroidal neovascularization (CNV), diabetic macular edema (DME), DRUSEN, and NORMAL in optical coherence tomography (OCT) images. The proposed classification algorithm adopted an ensemble of four classification model instances to identify retinal OCT images, each of which was based on an improved residual neural network (ResNet50). The experiment followed a patient-level 10-fold cross-validation process, on development retinal OCT image dataset. The proposed approach achieved 0.973 (95% confidence interval [CI], 0.971-0.975) classification accuracy, 0.963 (95% CI, 0.960-0.966) sensitivity, and 0.985 (95% CI, 0.983-0.987) specificity at the B-scan level, achieving a matching or exceeding performance to that of ophthalmologists with significant clinical experience. Other performance measures used in the study were the area under receiver operating characteristic curve (AUC) and kappa value. The observations of the study implied that multi-ResNet50 ensembling was a useful technique when the availability of medical images was limited. In addition, we performed qualitative evaluation of model predictions, and occlusion testing to understand the decision-making process of our model. The paper provided an analytical discussion on misclassification and pathology regions identified by the occlusion testing also. Finally, we explored the effect of the integration of retinal OCT images and medical history data from patients on model performance.
视网膜疾病分类是医学应用中计算机辅助诊断(CAD)的一个重要问题。本文聚焦于一个四类分类问题,以自动检测光学相干断层扫描(OCT)图像中的脉络膜新生血管(CNV)、糖尿病性黄斑水肿(DME)、玻璃膜疣和正常情况。所提出的分类算法采用了四个分类模型实例的集成来识别视网膜OCT图像,每个实例都基于改进的残差神经网络(ResNet50)。实验在开发的视网膜OCT图像数据集上遵循患者级别的10折交叉验证过程。所提出的方法在B扫描级别实现了0.973(95%置信区间[CI],0.971 - 0.975)的分类准确率、0.963(95%CI,0.960 - 0.966)的灵敏度和0.985(95%CI,0.983 - 0.987)的特异性,其性能与具有丰富临床经验的眼科医生相当或超过他们。该研究中使用的其他性能指标是受试者操作特征曲线下面积(AUC)和kappa值。研究结果表明,当医学图像可用性有限时,多ResNet50集成是一种有用的技术。此外,我们对模型预测进行了定性评估,并进行了遮挡测试以了解模型的决策过程。本文还对遮挡测试识别出的错误分类和病理区域进行了分析讨论。最后,我们探讨了整合视网膜OCT图像和患者病史数据对模型性能的影响。