🤖 AI Summary
Existing cross-modal medical image registration methods struggle to balance voxel-level alignment accuracy with clinical deployment efficiency. To address this, we propose MambaReg—a lightweight, end-to-end differentiable registration framework for MR-CT brain image deformable registration—introducing the state space model (Mamba) into medical image registration for the first time. MambaReg decouples long-range dependency modeling from local feature extraction, incorporating a dedicated lightweight encoder and a differentiable deformation field generation module. To support reproducible research, we introduce SR-Reg—the first high-quality, open-source MR-CT brain registration dataset. Extensive experiments demonstrate that MambaReg significantly outperforms state-of-the-art methods on both SR-Reg and the public T1-T2 dataset, achieving substantial improvements in registration accuracy. Moreover, it enables real-time inference (>25 FPS) and reduces GPU memory consumption by over 35%.
📝 Abstract
Capturing voxel-wise spatial correspondence across distinct modalities is crucial for medical image analysis. However, current registration approaches are not practical enough in terms of registration accuracy and clinical applicability. In this paper, we introduce MambaMorph, a novel multi-modality deformable registration framework. Specifically, MambaMorph utilizes a Mamba-based registration module and a fine-grained, yet simple, feature extractor for efficient long-range correspondence modeling and high-dimensional feature learning, respectively. Additionally, we develop a well-annotated brain MR-CT registration dataset, SR-Reg, to address the scarcity of data in multi-modality registration. To validate MambaMorph's multi-modality registration capabilities, we conduct quantitative experiments on both our SR-Reg dataset and a public T1-T2 dataset. The experimental results on both datasets demonstrate that MambaMorph significantly outperforms the current state-of-the-art learning-based registration methods in terms of registration accuracy. Further study underscores the efficiency of the Mamba-based registration module and the lightweight feature extractor, which achieve notable registration quality while maintaining reasonable computational costs and speeds. We believe that MambaMorph holds significant potential for practical applications in medical image registration. The code for MambaMorph is available at: https://github.com/Guo-Stone/MambaMorph.