A Multiscale Attention Feature based TransformerResidual Combined Network for Retinal Vessel Segmentation

Accurate segmentation and recognition of retinal vessels is a very important medical image analysis technique, which enables clinicians to precisely locate and identify vessels and other tissues in fundus images. However, there are two problems with most existing U-net-based vessel segmentation models. The first is that retinal vessels have very low contrast with the image background, resulting in the loss of much detailed information. The second is that the complex curvature patterns of capillaries result in models that cannot accurately capture the continuity and coherence of the vessels. To solve these two problems, we propose a joint Transformer–Residual network based on a multiscale attention feature (MSAF) mechanism to effectively segment retinal vessels (MATR-Net). In MATR-Net, the convolutional layer in U-net is replaced with a Residual module and a dual encoder branch composed with Transformer to effectively capture the local information and global contextual information of retinal vessels. In addition, an MSAF module is proposed in the encoder part of this paper. By combining features of different scales to obtain more detailed pixels lost due to the pooling layer, the segmentation model effectively improves the feature extraction ability for capillaries with complex curvature patterns and accurately captures the continuity of vessels. To validate the effectiveness of MATR-Net, this study conducts comprehensive experiments on the DRIVE and STARE datasets and compares it with state-of-the-art deep learning models. The results show that MATR-Net exhibits excellent segmentation performance with Dice similarity coefficient and Precision of 84.57%, 80.78%, 84.18%, and 80.99% on DRIVE and STARE, respectively.