Purpose or Case Report: Purpose is to describe how FCMR is instrumental in diagnosis of congenital heart disease (CHD) and to present imaging findings and correlation in 50 fetuses with CHD.
Methods & Materials: 50 fetuses, 21 4/7-38 weeks gestation with known or suspected diagnoses of CHD underwent FCMR for confirmation of cardiac findings and/or diagnosis of associated fetal anomalies.

A pseudo ECG-gating technique enabled steady state free precession images of the heart in coronal, sagittal and axial planes. Fetal neurologic and body anatomy was imaged using T2 and T1 sequences.

FCMR findings were compared to fetal US and echo findings; prenatal diagnoses were correlated with postnatal echo, CMR and cardiac CTA.
Results: 8 of 50 fetuses were eliminated from study as fetal/postnatal echo, CT or MR was not available. In 42 fetuses CHD findings diagnosed on FCMR and fetal MR images were compared to fetal echo/US and/or postnatal cardiac imaging including echo, CMR and CT. Fetal echo was not available in 4 patients, postnatal cardiac imaging was not available in 16 patients.
65 FCMR CHD diagnoses included HLHS(10), VSD(9), anomalous pulmonary veins(7), TGA(4), TOF(3), DORV(2).
Fetal MR revealed additional anatomical findings including abnormalities of the lungs, bronchi, abdominal situs, intracranial abnormalities and skeletal dysplasia.
FCMR images were diagnostic of complex and non-complex diagnoses of CHD in 37(88%) of 42 fetuses confirmed by fetal echo; 2(5%) had normal hearts, 4(9%) did not have fetal echo.
Death occurred in 11 patients, fetal demise in 4(9.5%), early neonatal in 7(16.5%).
Postnatal cardiac imaging was available in 26(62%), confirming FCMR CHD findings in 25(96%). In 1 fetus diagnosis of VSD on FCMR was missed on prenatal echo and confirmed on postnatal imaging. In 1 fetus vascular ring suspected on FCMR was not found on postnatal imaging.
In 5(12%) fetuses FCMR findings of pulmonary lymphangiectasia, obstructed TAPVC, HLHS, and neurologic diagnoses guided decision making, genetic analysis and future genetic/fertility discussions, and end-of-life planning.
Conclusions: FCMR is an important diagnostic tool to confirm or clarify diagnosis of CHD which is most often made with echo. Fetal MR is known to be a highly sensitive and specific method for identification of non-cardiac imaging findings associated with CHD. Early knowledge of severity of and complexity of CHD and accompanying anomalies enables guidance for delivery planning, immediate postnatal care and opportunities for genetic counseling.