Synopsis

Fetal MRI is a not uncommon imaging procedure, most often performed to diagnose neurologic abnormalities. Increasingly fetal cardiac MRI is performed to confirm CHD findings found on fetal echocardiography and associated non-cardiovascular anomalies, especially in mid-to-late gestation fetuses.

This educational exhibit will provide guidance for image acquisition and show an extensive multi-modality case based library of fetal cardiac images, highlighting MRI findings, with correlation to postnatal imaging.

Purpose

The purpose of this educational exhibit is to show FCMR images of congenital heart disease (CHD) and anatomical findings associated with CHD. We will describe currently available FCMR image acquisition techniques and use a case-based approach to show a variety of CHD diagnosis and non-cardiovascular associations on fetal MRI, along with correlation to fetal echocardiography, prenatal ultrasound, and postnatal imaging. Teaching points to highlight the added value of FCMR in diagnosis and prognosis will be added.

Materials and Methods

50 fetuses, 21 4/7-38 weeks gestation with known, suspected and unknown diagnoses of CHD underwent FCMR either for confirmation of cardiac findings and/or for diagnosis of associated fetal anomalies, including neurological, renal, pulmonary or musculoskeletal systems.
FCMR was performed using a pseudo ECG-gating technique to generate an artificial ECG trace to enable steady state free precession images of the heart in coronal, sagittal and axial planes. We will describe other techniques currently available, Doppler US and integrated ECG methods.
FCMR findings will be shown along with correlative fetal echo and postnatal echo, cardiac MR and cardiac CTA images.

Results

65 CHD diagnoses made with FCMR included hypoplastic left heart syndrome (10), ventricular septal defect (9), anomalous pulmonary veins (7), transposition of the great arteries (4), tetralogy of Fallot (3), and double outlet right ventricle (2). Fetal MR revealed additional important anatomical findings in fetuses with CHD including abnormalities of the pulmonary parenchyma, bronchi, abdominal visceral situs, intracranial abnormalities (brain malformations, stroke, ventriculomegaly) and skeletal dysplasia.

Conclusion

FCMR is an important diagnostic tool used to confirm or clarify the diagnosis of CHD which is most often initially 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 and immediate postnatal care and opportunities for possible genetic counseling for parents.