Value of MRI in the diagnosis of fetal aortic arch anomalies

Objective To explore the value of MRI in the diagnosis of fetal aortic arch anomalies. Methods We retrospectively collected 10 fetuses with aortic arch anomalies indicated by prenatal ultrasound and underwent MR examination and were subsequently proven by autopsy or post-birth follow-up from 320 pregnant women. We focused on the observations of the location of the aortic arch and brachiocephalic artery anomalies, the locations of the liver and stomach in the abdominal cavity, and the large vessels in abdomen. The above-mentioned finding were compared with prenatal ultrasound and follow-up findings. Results Of 10 cases, right aortic arch with aberrant left subclavian artery was seen in 7 cases, right aortic arch with the mirror branch, left aortic arch with aberrant right subclavian artery, right aortic arch with aberrant left subclavian artery combined with cervical aortic arch and double aortic arch was seen in 1 case, respectively. All aortic arch anomalies detected by MRI were consistent with post-birth or autopsy findings. Ultrasound misdiagnosed aortic branch malformation in 5 places, which included right aortic arch but misdiagnosed aberrant left subclavian artery in 2 cases, right aortic arch never diagnosed mirror branch anomaly in 1 case, right aortic arch with left subclavian artery misdiagnosed cervical aortic arch in 1 case, left atrial isomerism but misdiagnosed left aortic arch with aberrant right subclavian artery in 1 case; One double aortic arch was misdiagnosed as right aortic arch with aberrant left subclavian artery in ultrasound. Conclusion Fetal cardiovascular MRI is an effective and supplementary examination to complement ultrasound in diagnosis of fetal aortic arch anomalies. Key words: Fetus; Aorta,thoracic; Vascular malformations; Magnetic resonance imaging