As the initial step of multimodal medical image registration, the accuracy and speed of registration will largely affect the effect of medical image fusion. Due to the large difference in grayscale and texture structure of multimodal medical images, it is difficult to extract correlating features, resulting in low registration accuracy. This paper proposes a multi-layer feature fusion registration network, parallel extraction of features of the fix image and moving image, and the multimodal feature is gradually fused by using the dual-input spatial attention module in the multi-layer structure, obtaining their correlation and mapping such correlation to image registration transformation. At the same time, the structural information loss term guidance network based on dense symmetric scale invariant feature transform is introduced for iterative optimization to achieve accurate unsupervised registration.
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