论文标题
用于医学图像细分的分布式对比度学习
Distributed Contrastive Learning for Medical Image Segmentation
论文作者
论文摘要
有监督的深度学习需要大量标记的数据才能实现高性能。但是,在医学成像分析中,每个站点可能只有有限的数据和标签,这使得学习无效。联合学习(FL)可以从分散数据中学习共享模型。但是传统的FL需要全标签的数据进行培训,这是非常昂贵的。自我监督的对比学习(CL)可以从未标记的数据中学习以进行预训练,然后进行微调,以有限的注释。但是,在FL中采用CL时,每个站点上的数据多样性有限,使联合对比度学习(FCL)无效。在这项工作中,我们提出了两个联合联合的自我监督学习框架,用于体积的医学图像分割,注释有限。第一个具有高精度,并适合具有高速连接的高性能服务器。第二个具有较低的通信成本,适用于移动设备。在第一个框架中,在FCL期间交换了功能,以向每个站点提供各种对比度数据,以使其有效的本地CL,同时将原始数据保持私密。全局结构匹配将不同站点之间统一特征空间的本地和远程特征对齐。在第二个框架中,为了降低特征交换的通信成本,我们提出了一种优化的方法FCLOPT,该方法不依赖于负样本。为了减少模型下载的通信,我们提出了预测目标网络参数的预测目标网络更新(PTNU)。基于PTNU,我们建议距离预测(DP)以删除目标网络的大多数上传。与最新技术相比,在心脏MRI数据集上的实验表明,提出的两个框架显着改善了分割和泛化性能。
Supervised deep learning needs a large amount of labeled data to achieve high performance. However, in medical imaging analysis, each site may only have a limited amount of data and labels, which makes learning ineffective. Federated learning (FL) can learn a shared model from decentralized data. But traditional FL requires fully-labeled data for training, which is very expensive to obtain. Self-supervised contrastive learning (CL) can learn from unlabeled data for pre-training, followed by fine-tuning with limited annotations. However, when adopting CL in FL, the limited data diversity on each site makes federated contrastive learning (FCL) ineffective. In this work, we propose two federated self-supervised learning frameworks for volumetric medical image segmentation with limited annotations. The first one features high accuracy and fits high-performance servers with high-speed connections. The second one features lower communication costs, suitable for mobile devices. In the first framework, features are exchanged during FCL to provide diverse contrastive data to each site for effective local CL while keeping raw data private. Global structural matching aligns local and remote features for a unified feature space among different sites. In the second framework, to reduce the communication cost for feature exchanging, we propose an optimized method FCLOpt that does not rely on negative samples. To reduce the communications of model download, we propose the predictive target network update (PTNU) that predicts the parameters of the target network. Based on PTNU, we propose the distance prediction (DP) to remove most of the uploads of the target network. Experiments on a cardiac MRI dataset show the proposed two frameworks substantially improve the segmentation and generalization performance compared with state-of-the-art techniques.