EP09.51: Feasibility of fetal cardiac MRI in the prenatal evaluation of congenital heart defects in comparison to ultrasound

Congenital heart defects (CHD) are the most common severe birth defects. They are often life-threatening, resulting in a clinical need for precise prenatal assessment to provide best possible postnatal care. MRI of the fetal heart recently became feasible with the advent of novel gating techniques that allow for fetal cardiac rhythm monitoring within the scanner, but its feasibility has not yet been systematically evaluated in pregnancies with fetal CHD. We therefore assessed the value of fetal cardiac MRI in the prenatal management of these pregnancies. This case-control study yet evaluated 21 singleton pregnancies, consisting of 12 fetuses with diagnosis of CHD and 9 healthy control fetuses (HC). Diagnosis of CHD was refined by a cardiopediatrician. Subjects were referred to the MRI after US examination at 30 weeks onwards. All MRI images were reviewed by a single blinded operator also rating image quality of cardiac sequences from 0 (not usable) to 5 (high image quality). Correlation between MRI findings and US diagnosis was assessed. Fetal cardiac MRI was feasible in 19 out of 21 patients (91%; image quality score >0) due to fetal movement in n = 2 cases. Among, in n = 6 (31.6%), n = 10 (52.6%) and in n = 3 (15.8%) cases image quality was rated high (image quality score 5), medium (image quality score 3-4) and poor (image quality score 1-2), respectively. In the 12 fetuses with CHD, fetal cardiac MRI was capable to fully confirm US-diagnosis in n = 8 (66.7%) and partly in n = 4 (33.3%) cases, mostly due to incomplete recording of structures of interest. Agreement between MRI and US was good (κ-value 0.79 with an accuracy of 0.895). Our preliminary study suggests a similar performance of MRI and US. With improvements in sequences, gating techniques and operator experience, MRI examination could soon become an essential part of the prenatal management of CHD, not only to look for associated abnormalities but also to reinforce the assessment of heart disease itself.