Fig. 6.

The proposed outlier-robust high-resolution volume reconstruction method for fetal brain MRI. As part of a two-step motion-correction/volumetric reconstruction cycle, we propose an effective robust SRR method for complete outlier rejection that relies on a single hyperparameter only and retains a linear least-squares formulation. A fast template-space alignment, which is robust also for pathological brains, is achieved by using a principal brain axes (PBA)-initialized rigid volume-to-template registration based on symmetric block-matching.