Flow quantification in the great vessels for third trimester fetal coarctation using 3D motion corrected black blood imaging and 4D flow MRI

Motivation: Fetal 4D flow MRI can improve prenatal aortic coarctation diagnosis, but vessel segmentation for fetal 4D flow is challenging and requires expertise. Goal(s): To test the flow quantification performance and interobserver dependence of fetal 4D flow with motion corrected black blood (BB) segmentation for volunteers and coarctation patients. Approach: BB imaging was motion corrected and registered to 4D flow. Net flow was quantified based on manual segmentation of the great vessels done by two observers. Results: BB segmentation-based flow quantification was less observer dependent and better captured distal aortic arch flow in coarctation patients than the conventional 4D flow analysis. Impact: Vessel segmentation for fetal 4D flow is challenging, but our approach combining 4D flow and motion corrected black blood imaging may facilitate segmentation and flow quantification of the distal aortic arch for coarctation patients, potentially improving diagnosis of prenatal coarctation.