4D iterative reconstruction of brain fMRI in the moving fetus
This work addresses a domain-specific challenge in fetal brain imaging by improving fMRI reconstruction for clinical application, though it appears incremental as it builds on prior motion estimation methods.
The paper tackled the problem of unpredictable fetal motion degrading fMRI image quality by proposing a 4D iterative reconstruction method, which showed improved reconstruction quality compared to conventional 3D interpolation in clinical fetal fMRI data.
Resting-state functional Magnetic Resonance Imaging (fMRI) is a powerful imaging technique for studying functional development of the brain in utero. However, unpredictable and excessive movement of fetuses has limited clinical application since it causes substantial signal fluctuations which can systematically alter observed patterns of functional connectivity. Previous studies have focused on the accurate estimation of the motion parameters in case of large fetal head movement and used a 3D single step interpolation approach at each timepoint to recover motion-free fMRI images. This does not guarantee that the reconstructed image corresponds to the minimum error representation of fMRI time series given the acquired data. Here, we propose a novel technique based on four dimensional iterative reconstruction of the scattered slices acquired during fetal fMRI. The accuracy of the proposed method was quantitatively evaluated on a group of real clinical fMRI fetuses. The results indicate improvements of reconstruction quality compared to the conventional 3D interpolation approach.