Background:Identifying fetuses at risk of severe neonatal coarctation of the aorta (CoA) can be lifesaving but is notoriously challenging in clinical practice with a high rate of false positives. Novel fetal 3-dimensional and phase-contrast magnetic resonance imaging (MRI) offers an unprecedented means of assessing the human fetal cardiovascular system before birth. We performed detailed MRI assessment of fetal vascular morphology and flows in a cohort of fetuses with suspected CoA, correlated with the need for postnatal intervention.Methods:Women carrying a fetus with suspected CoA on echocardiography were referred for MRI assessment between 26 and 36 weeks of gestation, including high-resolution motion-corrected 3-dimensional volumes of the fetal heart and phase-contrast flow sequences gated with metric optimized gating. The relationship between aortic geometry and vascular flows was then analyzed and compared with postnatal outcome.Results:Seventy-two patients (51 with suspected fetal CoA and 21 healthy controls) underwent fetal MRI with motion-corrected 3-dimensional vascular reconstructions. Vascular flow measurements from phase-contrast sequences were available in 53 patients. In the CoA group, 25 of 51 (49%) required surgical repair of coarctation after birth; the remaining 26 of 51 (51%) were discharged without neonatal intervention. Reduced blood flow in the fetal ascending aorta and at the aortic isthmus was associated with increasing angulation (P=0.005) and proximal displacement (P=0.006) of the isthmus and was seen in both true positive and false positive cases. A multivariate logistic regression model including aortic flow and isthmal displacement explained 78% of the variation in outcome and correctly predicted the need for intervention in 93% of cases.Conclusions:Reduced blood flow though the left heart is associated with important configurational changes at the aortic isthmus in fetal life, predisposing to CoA when the arterial duct closes after birth. Novel fetal MRI techniques may have a role in both understanding and accurately predicting severe neonatal CoA.

中文翻译：

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使用胎儿心脏磁共振成像分析疑似主动脉缩窄病例的三维弓解剖结构、血管血流和产后结果

背景：识别有严重新生儿主动脉缩窄 (CoA) 风险的胎儿可以挽救生命，但在临床实践中却充满挑战，假阳性率很高。新型胎儿 3 维相位对比磁共振成像 (MRI) 提供了一种前所未有的方法来评估出生前的人类胎儿心血管系统。我们对一组疑似 CoA 胎儿的胎儿血管形态和血流进行了详细的 MRI 评估，并与产后干预的需要相关。方法：怀有超声心动图疑似 CoA 胎儿的女性在出生后 26 至 36 周期间转诊接受 MRI 评估。妊娠，包括胎儿心脏的高分辨率运动校正 3 维体积和通过度量优化门控进行门控的相衬血流序列。然后分析主动脉几何形状和血管流量之间的关系，并与出生后结果进行比较。结果：72 名患者（51 名疑似胎儿 CoA 患者和 21 名健康对照者）接受了胎儿 MRI 和运动校正 3 维血管重建。对 53 名患者进行了相位对比序列的血管流量测量。在 CoA 组中，51 例中有 25 例（49%）在出生后需要进行缩窄手术修复；51 名患者中的其余 26 名（51%）在没有新生儿干预的情况下出院。胎儿升主动脉和主动脉峡部血流量减少与峡部角度增加（P = 0.005）和近端移位（P = 0.006）相关，并且在真阳性和假阳性病例中均可见。包括主动脉流量和峡部移位的多变量逻辑回归模型解释了 78% 的结果变化，并正确预测了 93% 病例的干预需求。结论：左心血流量减少与主动脉的重要构型变化相关胎儿时期存在峡部，出生后动脉管关闭时易患 CoA。新型胎儿 MRI 技术可能在理解和准确预测严重新生儿 CoA 方面发挥作用。