Deep learning models trained on medical images from a source domain (e.g. imaging modality) often fail when deployed on images from a different target domain, despite imaging common anatomical structures. Deep unsupervised domain adaptation (UDA) aims to improve the performance of a deep neural network model on a target domain, using solely unlabelled target domain data and labelled source domain data. However, current state-of-the-art methods exhibit reduced performance when target data is scarce. In this work, we introduce a new data efficient UDA method for multi-domain medical image segmentation. The proposed method combines a novel VAE-based feature prior matching, which is data-efficient, and domain adversarial training to learn a shared domain-invariant latent space which is exploited during segmentation. Our method is evaluated on a public multi-modality cardiac image segmentation dataset by adapting from the labelled source domain (3D MRI) to the unlabelled target domain (3D CT). We show that by using only one single unlabelled 3D CT scan, the proposed architecture outperforms the state-of-the-art in the same setting. Finally, we perform ablation studies on prior matching and domain adversarial training to shed light on the theoretical grounding of the proposed method.

本文提出了一种新的数据有效的多域医学图像分割的深度无监督领域自适应方法，该方法结合了基于变分自编码器的特征先验匹配和域对抗训练，以学习共享的域不变潜在空间进行分割。在公共多模态心脏图像分割数据集上评估，在仅使用一个未标记的3D CT扫描的情况下，该方法在相同的设定下胜过现有的技术。最后，我们对先验匹配和域对抗训练进行了消融研究，以阐明所提出方法的理论基础。

跨模态图像分割的高效无监督领域自适应算法