Prenatal cardiac magnetic resonance imaging of right aortic arch with mirror image branching and retroesophageal left ductus arteriosus.

OBJECTIVE

To evaluate the utility of fetal cardiac magnetic resonance imaging (MRI) in diagnosing right aortic arch with mirror image branching and retroesophageal left ductus arteriosus (RLDA).

METHODS

This retrospective study included six infants diagnosed with right aortic arch with mirror image branching and RLDA postnatally by cardiac computed tomography (CT) that had fetal echocardiography (echo) and MRI initially performed. The six fetal MRI cases were examined using 1.5 T MRI unit. Steady-state free precession (SSFP) sequence and single-shot turbo spin echo (SSTSE) sequence were used to evaluate the fetal great vessels and airway. The gestational age of six fetuses at time of fetal MRI ranged from 23 to 35 weeks (mean, 26.7 weeks).

RESULTS

Of six cases with mirror image right aortic arch and RLDA confirmed by postnatal CT, 4/6 were correctly diagnosed by fetal cardiac MRI and 3/6 were correctly diagnosed by prenatal echo. All six cases were not associated with other congenital heart defect. All ductus arteriosus were closed after birth.

CONCLUSIONS

Fetal cardiac MRI can be a useful adjunct for evaluating fetal right aortic arch with mirror-image and RLDA.