Deep neural networks have been a prevailing technique in the field of medical image processing. However, the most popular convolutional neural networks (CNNs) based methods for medical image segmentation are imperfect because they cannot adequately model long-range pixel relations. Transformers and the self-attention mechanism are recently proposed to effectively learn long-range dependencies by modeling all pairs of word-to-word attention regardless of their positions. The idea has also been extended to the computer vision field by creating and treating image patches as embeddings. Considering the computation complexity for whole image self-attention, current transformer-based models settle for a rigid partitioning scheme that would potentially lose informative relations. Besides, current medical transformers model global context on full resolution images, leading to unnecessary computation costs. To address these issues, we developed a novel method to integrate multi-scale attention and CNN feature extraction using a pyramidal network architecture, namely Pyramid Medical Transformer (PMTrans). The PMTrans captured multi-range relations by working on multi-resolution images. An adaptive partitioning scheme was implemented to retain informative relations and to access different receptive fields efficiently. Experimental results on two medical image datasets, gland segmentation and MoNuSeg datasets, showed that PMTrans outperformed the latest CNN-based and transformer-based models for medical image segmentation.

通过应用金字塔形网络结构、多尺度注意力和 CNN 特征提取，我们提出了一种称为金字塔医疗变压器（PMTrans）的新型方法，可以更好地处理医学图像分割任务。在三个医学图像数据集上的实验结果表明，PMTrans 相较于最新的基于 CNN 和变压器的模型，具有更好的性能。

金字塔医疗转换器用于医学图像分割