A4-Unet: Deformable Multi-Scale Attention Network for Brain Tumor Segmentation

TL;DR

A4-Unet is a novel CNN architecture that integrates deformable multi-scale attention mechanisms to improve brain tumor segmentation accuracy across multiple MRI datasets, achieving state-of-the-art results.

Contribution

The paper introduces A4-Unet, a new network with deformable large kernel attention, swin spatial pyramid pooling, and combined attention modules for enhanced tumor segmentation.

Findings

Achieves 94.4% Dice score on BraTS 2020

Sets new state-of-the-art benchmarks on multiple datasets

Effectively captures multi-scale and long-distance dependencies

Abstract

Brain tumor segmentation models have aided diagnosis in recent years. However, they face MRI complexity and variability challenges, including irregular shapes and unclear boundaries, leading to noise, misclassification, and incomplete segmentation, thereby limiting accuracy. To address these issues, we adhere to an outstanding Convolutional Neural Networks (CNNs) design paradigm and propose a novel network named A4-Unet. In A4-Unet, Deformable Large Kernel Attention (DLKA) is incorporated in the encoder, allowing for improved capture of multi-scale tumors. Swin Spatial Pyramid Pooling (SSPP) with cross-channel attention is employed in a bottleneck further to study long-distance dependencies within images and channel relationships. To enhance accuracy, a Combined Attention Module (CAM) with Discrete Cosine Transform (DCT) orthogonality for channel weighting and convolutional element-wise multiplication is introduced for spatial weighting in the decoder. Attention gates (AG) are added in the skip connection to highlight the foreground while suppressing irrelevant background information. The proposed network is evaluated on three authoritative MRI brain tumor benchmarks and a proprietary dataset, and it achieves a 94.4% Dice score on the BraTS 2020 dataset, thereby establishing multiple new state-of-the-art benchmarks. The code is available here: https://github.com/WendyWAAAAANG/A4-Unet.