Unsupervised domain adaptation (UDA) aims to learn a model trained on source domain and performs well on unlabeled target domain. In medical image segmentation field, most existing UDA methods depend on adversarial learning to address the domain gap between different image modalities, which is ineffective due to its complicated training process. In this paper, we propose a simple yet effective UDA method based on frequency and spatial domain transfer uner multi-teacher distillation framework. In the frequency domain, we first introduce non-subsampled contourlet transform for identifying domain-invariant and domain-variant frequency components (DIFs and DVFs), and then keep the DIFs unchanged while replacing the DVFs of the source domain images with that of the target domain images to narrow the domain gap. In the spatial domain, we propose a batch momentum update-based histogram matching strategy to reduce the domain-variant image style bias. Experiments on two cross-modality medical image segmentation datasets (cardiac, abdominal) show that our proposed method achieves superior performance compared to state-of-the-art methods.

本文提出了一种基于多教师蒸馏框架下的频率和空间域转移的简单有效的无监督领域自适应方法，其中使用非下采样轮廓波束变换来识别域不变分量和域变分量，并使用批次动量更新的直方图匹配策略来减少图像风格偏差。两个医疗图像分割数据集上的实验表明，我们的方法优于现有最先进的方法。

基于跨模态域适应的医学图像分割中频率和空间域内的领域差异降低