SVRMamba: Slice-to-Volume Reconstruction from Multiple MRI Stacks with Slice Sequence Guided Mamba

In fetal magnetic resonance imaging (MRI), slice-to-volume reconstruction (SVR) involves the computational creation of a 3D volume from multiple stacks of 2D slices. This process is challenging due to slice misalignment and image noise. Current state-of-the-art (SOTA) SVR methods typically employ coarse-to-fine techniques that iteratively refine slice-to-volume motion correction and 3D volume reconstruction. However, both processes are inherently inefficient, making these methods time-consuming and prone to errors. This often results in less robust and accurate outcomes, primarily due to insufficient modeling of the spatial relationships between slices. Typically, 2D fetal MRI slices are acquired using the interleave sequence, which first acquires the odd slices and then the even slices in one stack. To this end, we propose a novel Mamba-based framework called SVRMamba, which integrates slice-to-volume reconstruction with slice sequence-guided state space modeling. Specifically, our approach reformulates Mamba’s unidirectional scanning into a slice sequence-guided odd-even directional scanning method and marks the slice positions using sequence embedding tokens. This enables the network to learn the slice relationships and spatial sequences, enhancing fetal MRI SVR motion correction performance. We further integrate a convolutional neural network (CNN)-based interpolation network that generates a noise-suppressed 3D reconstruction by leveraging the predicted motion for each slice. This framework notably enhances 3D fetal brain SVR, delivering substantial improvements in both reconstruction speed and overall performance. Extensive experiments conducted on various benchmark and clinical datasets demonstrate that SVRMamba significantly outperforms existing SOTA methods, delivering comparable results with a remarkable sixtyfold increase in reconstruction speed.