Temporal Registration in In-Utero Volumetric MRI Time Series
This addresses motion artifacts in fetal MRI for medical imaging applications, but it is incremental as it builds on existing registration methods.
The paper tackles motion correction in in-utero MRI time series by using a Markov assumption and hidden Markov model for temporal registration, resulting in improved segmentation propagation accuracy.
We present a robust method to correct for motion and deformations for in-utero volumetric MRI time series. Spatio-temporal analysis of dynamic MRI requires robust alignment across time in the presence of substantial and unpredictable motion. We make a Markov assumption on the nature of deformations to take advantage of the temporal structure in the image data. Forward message passing in the corresponding hidden Markov model (HMM) yields an estimation algorithm that only has to account for relatively small motion between consecutive frames. We demonstrate the utility of the temporal model by showing that its use improves the accuracy of the segmentation propagation through temporal registration. Our results suggest that the proposed model captures accurately the temporal dynamics of deformations in in-utero MRI time series.