A New Unsupervised Learning Method for 3D Deformable Medical Image Registration

Abstract

Accurate registration of medical images is vital for doctor's diagnosis and quantitative analysis. In this paper, we propose a new unsupervised learning network SA-VoxelMorph for 3D deformable medical image registration. In this paper, we design a novel network architecture SAU-Net by introducing a new Binary Spatial Attention Module (BSAM) into skip connection of 3D U-Net, which can make full use of the spatial information extracted from the encoding and corresponding decoding stage. Moreover, from variational method, control function can better control the generation of registration field φ. Therefore, we also propose a new registration loss function with novel smoothing term based on optimal control method to generate better φ. We verify our method on two datasets including ADNI and PPMI, and obtain excellent results on magnetic resonance image (MRI) registration with higher average Dice scores and better diffeomorphic registration fields compared with other state-of-the-art methods. The experimental results show the method can achieve better performance in brain MRI registration.