Reliability of fetal 4D flow in healthy volunteers and patients with suspected congenital cardiovascular anomalies

Motivation: Fetal 4D flow provides useful information related to cardiovascular structure and function, but its reliability is not yet defined. Goal(s): Here, we seek to define the accuracy, precision, internal consistency, and repeatability of fetal 4D flow. Approach: Pregnant women in their third trimester with healthy developing fetuses (N=22) and fetuses with suspected cardiovascular anomalies (N=12) were scanned with 2D phase contrast and 4D flow sequences. Quantitative flow metrics were compared. Results: 4D flow underestimated net flow in the great vessels relative to 2D-PC, but had reasonable precision, internal consistency, and repeatability. Fetal 4D flow can reliably measure percentage contributions from various vascular territories. Impact: Fetal 4D flow allows for quantitative hemodynamic evaluation of the fetal cardiovascular system with good precision, internal consistency, and repeatability. Flow was underestimated relative to 2D-PC, therefore presently percent contribution from various vascular territories is the most appropriate clinical endpoint.