This paper introduces an unsupervised adversarial similarity network for image registration. Unlike existing deep learning registration frameworks,our approach does not require ground-truth deformations and specific similarity metrics. We connect a registration network and a discrimination network with adeformable transformation layer. The registration network is trained with feedback from the discrimination network, which is designed to judge whether a pair of registered images are sufficiently similar. Using adversarial training, the registration network is trained to predict deformations that are accurate enough to fool the discrimination network. Experiments on four brain MRI datasets indicate that our method yields registration performance that is promising in both accuracy and efficiency compared with state-of-the-art registration methods, including those based on deep learning.
