Potential role of fetal cardiac evaluation with magnetic resonance imaging: preliminary experience

To report our experience with magnetic resonance imaging (MRI) in fetal heart evaluation.

Two radiologists examined 31 MRI of fetuses with no ultrasound (US) evidence of cardio-thoracic anomalies. T2-weighted half-Fourier single-shot turbo spin-echo sequences were acquired for anatomic evaluation; fast imaging with steady-state free precession (TrueFISP) and cine-MR sequences with real-time steady-state free precession oriented like standard fetal echocardiographic projections were acquired for the characterization of cardiovascular morphology and function.

In every case, MRI assessed the viscero-atrial situs. The four-chamber view and the short-axis view of the left ventricle were obtained in all fetuses, the long-axis view of the aortic arch in 28, the long-axis view of the ductus arteriosus in 17, the five-chamber view in 12, the long-axis of the left ventricle in 9, the three-vessel view in 7, the tricuspid-aortic view in 3, and the transverse view of the aortic arch and the angulated view of the arch and the ductus arteriosus simultaneously in 2 fetuses.

Our preliminary experience demonstrates the feasibility to visualize the fetal heart with routine fetal MRI protocols in particular, by means of acquisition of TrueFISP imaging (morphological study) and real-time cine-MRI (dynamic study), potentially making MRI a second-level tool to add to fetal echocardiography in the prenatal study of congenital cardiac malformations.