Augmented hemodynamic quantification of the fetal cardiovascular system using 4D flow MRI and slice to volume 3D black blood imaging

Motivation: Small blood vessel size relative to spatial resolution in fetal 4D flow MRI makes segmentation and flow quantification difficult. Goal(s): To quantify blood flow from fetal 4D flow using black blood imaging-based segmentation and to compare hemodynamic results to 4D flow-only approach. We hypothesize black blood will provide better flow delineation for complex anatomies. Approach: The great vessels were segmented from 4D flow and black blood for volunteers and coarctation cases; flow volumes were compared after alignment of segmentations. Results: Black blood underestimated flow volume but captured vessel geometry and flow features 4D flow segmentation missed in several cases of coarctation. Impact: While the combination of black blood imaging and fetal 4D flow did not offer flow quantification comparable to conventional 4D flow approach, its potential of capturing coarctation flow may assist prenatal diagnosis of coarctation, which is challenging solely with ultrasound.