Bettina Hergert ^* Manuela Tavares de Sousa ^* Jochen Herrmann ^* Peter Bannas Lukas Huber ^* Sophie Götz ^* Kurt Hecher ^* Gerhard Adam ^* Maryam Dargahpour Barough ^* Björn Schönnagel ^*

• University Medical Center Hamburg-Eppendorf, Hamburg, Germany

Objectives: To investigate the diagnostic performance of fetal cardiovascular magnetic resonance imaging (MRI) using Doppler ultrasound (DUS) gating for the evaluation of the standardized five axial views in comparison with fetal echocardiography.In this prospective study 29 pregnant women (median: 34.4 weeks of gestation) underwent fetal cardiovascular MRI using DUS gating at 3 Tesla. The standardized five axial views in prenatal screening (fetal abdomen, four-chamber view, left ventricular outflow tract, right ventricular outflow tract, and three-vessel view) were independently assessed and analysed by both fetal MRI and fetal echocardiography on the same day. Image analysis included qualitative assessment and quantitative measurements of cardiovascular structures. MR image quality was assessed using a 4-point scale (from 1=low to 4=excellent). Postnatal echocardiography was performed for validation.Results: 17/28 fetuses (60.7%) had pathological findings (16 congenital heart defect (CHD), one diaphragmatic hernia) in prenatal echocardiography. One fetus was excluded due to severe motion. Overall sensitivity and specificity in detecting fetal cardiac abnormalities was 88% and 100%, respectively, for fetal MRI and 100% and 100 % for fetal echocardiography. MR image quality for evaluation of cardiac structures was high with a mean score of 2.8 (±0.8) (score 4: 15.9%, score 3: 53.8%, score 2: 19.3%, score 1: 11%). Quantitative measurements did not differ between fetal cardiovascular MRI and fetal echocardiography (all p>0.05).Diagnostic performance of fetal cardiovascular MRI using DUS gating was comparable to fetal echocardiography. Fetal cardiovascular MRI using DUS gating might be a valuable diagnostic adjunct for the prenatal evaluation of CHD.