Super-Resolution Reconstruction of Fetal Brain MRI with Prior Anatomical Knowledge

Super-resolution reconstruction (SRR) of fetal brain MRI from motion-corrupted thick-slice stacks can provide high-resolution isotropic 3Dimages that are vital for prenatal examination and quantification of brain development. Existing fetal brain SRRmethods generally rely on a two-stage optimization procedure by performing rigid slice-to-volume registration and volumetric reconstruction in an alternating manner. Despite their advantages, these methods have not considered additional guidance from external anatomical priors, resulting in unsatisfactory performance in various challenging cases. To address this issue, we propose a novel Prior Anatomical Knowledge guided fetal brain Super-Resolution Reconstruction method, namely PAK-SRR. In PAK-SRR, we consider two key kinds of prior anatomical information. First, we integrate the anatomical prior provided by tissue segmentation into both the slice-tovolume registration and volumetric reconstruction to enforce registration consistency on boundaries, effectively alleviating misregistration caused by blurry tissue boundaries of brain. Second, to enrich the structural details of the reconstructed images, we further employ longitudinal fetal brain atlases to guide volumetric reconstruction. Extensive experiments on multi-site clinical datasets demonstrate that our PAK-SRR significantly outperforms the state-of-the-art SRR methods for fetal brain MRI, quantitatively and qualitatively. Our code is publicly available at https://git hub.com/sj-huang/PAK- SRR for reproducibility and further research.