Third Trimester Fetal 4D Flow MRI with Motion Correction

Motivation: Fetal 4D flow MRI is limited by the presence of motion from maternal breathing and stochastic fetal movements Goal(s): To demonstrate the effects of maternal respiratory and fetal bulk motion correction with outlier rejection in 4D flow MRI Approach: One or more 4D flow datasets were acquired in 17 fetuses, followed by maternal respiratory gating and bulk motion correction, and compressed sensing (CS) reconstruction with outlier rejection. Uncorrected (CS without motion correction) reconstructions served as reference. Results: Twenty-nine scans were evaluated. Motion correction recovered 8/13 heavily motion-corrupted scans, and provided improved conservation of mass values (uncorrected=14%(24%),corrected=5%(9%),p=0.002) at the ductal insertion at the aorta. Impact: The proposed method of maternal respiratory gating and fetal bulk motion correction combined with data outlier rejection in fetal 4D flow led to a reduction in motion artifacts, recovery of previously corrupted scans, and improved conservation of mass.