Efficiently capturing multi-scale information and building long-range dependencies among pixels are essential for medical image segmentation because of the various sizes and shapes of the lesion regions or organs. In this paper, we present Multi-scale Cross-axis Attention (MCA) to solve the above challenging issues based on the efficient axial attention. Instead of simply connecting axial attention along the horizontal and vertical directions sequentially, we propose to calculate dual cross attentions between two parallel axial attentions to capture global information better. To process the significant variations of lesion regions or organs in individual sizes and shapes, we also use multiple convolutions of strip-shape kernels with different kernel sizes in each axial attention path to improve the efficiency of the proposed MCA in encoding spatial information. We build the proposed MCA upon the MSCAN backbone, yielding our network, termed MCANet. Our MCANet with only 4M+ parameters performs even better than most previous works with heavy backbones (e.g., Swin Transformer) on four challenging tasks, including skin lesion segmentation, nuclei segmentation, abdominal multi-organ segmentation, and polyp segmentation. Code is available at https:// github.com/ haoshao-nku/ medical seg.git.

在本文中，我们提出了基于高效轴向注意力的多尺度交叉轴向注意力（MCA）来解决医学图像分割中的多尺度信息获取和像素之间的长程依赖问题，通过计算两个平行轴向注意力之间的双交叉注意力来更好地捕捉全局信息。同时，我们还使用不同核尺寸的多个条状卷积来处理病变区域或器官的显著变化，以提高空间信息的编码效率。经过实验证明，我们的网络MCANet仅具有4M+参数，在皮肤病变分割、细胞核分割、腹部多器官分割和息肉分割等四个具有挑战性的任务上，表现比大型骨干模型（如Swin Transformer）更出色。

MCANet：多尺度交叉轴注意力的医学图像分割