目的 总结胎儿镜面右位主动脉弓伴左位动脉导管连接降主动脉（MRAA-LDA-DAO）超声特征；探讨升弓部冠状切面在MRAA-LDA-DAO鉴别诊断中的价值。方法 回顾性分析经产后超声心动图或CT血管三维重建证实的4例胎儿MRAA-LDA-DAO的超声心动图资料，总结其在三血管气管切面和升弓部冠状切面的声像图特点。结果 本院产前超声诊断4例MRAA-LDA-DAO，其中修正外院诊断2例。MRAA-LDA-DAO超声表现：三血管气管切面见“U”或“”形血管环；升弓部冠状切面见升主动脉向左上方发出第一分支（左无名动脉）与动脉导管呈上下交叉关系。结论 MRAA-LDA-DAO 产前超声具有特征性表现；升弓部冠状切面在MRAA-LDA-DAO鉴别诊断中有重要价值。
Objective To summarize the echocardiographic characteristics of fetal mirror right aortic arch with left ductus arteriosus connecting descending aorta（MRAA-LDA-DAO）. To discuss the value of ascending arch coronal section in the differential diagnosis of MRAA-LDA-DAO. Methods Echocardiographic characteristics of 4 fetuses with MRAA-LDA-DAO confirmed by postnatal echocardiography or computed tomography angiography were reviewed. Sonographic features on three-vessel and trachea view（3VT） and ascending arch coronal section were summarized. Results Among 4 fetuses diagnosed as MRAA-LDA-DAO by prenatal ultrasound of our hospital, 2 cases diagnosed as double aortic arch by other hospital were corrected. Ultrasound characteristics were that U-shaped or -shaped vascular ring was formed on 3VT view and the first branch (the innominate artery) arise from the lateral wall of the ascending aorta and keep the “up and down” relationships with the LDA on ascending arch coronal section. Conclusions MRAA-LDA-DAO has some characteristic signs on echocardiography. Ascending arch coronal section are the most important differential diagnosis view for MRAA-LDA-DAO.
