摘要目的 探讨胎儿镜像右位主动脉弓形成血管环的超声特征.方法 回顾性分析16例单纯镜像右位主动脉弓与左位动脉导管弓形成血管环的胎儿超声心动图图像,总结其超声特征.结果 ①三血管+气管切面显示动脉导管弓均走形于气管的左侧,与右位主动脉弓形成“U”型血管环;②三血管+气管切面或稍高的纵隔横切面显示,左无名动脉向左侧平直走形,在上方与动脉导管呈交叉走形,两者相邻紧密;③双弓切面及动脉导管弓长轴切面连续扫查显示左无名动脉未与降主动脉或动脉导管相连接,不参与血管环的形成;④彩色多普勒对诊断本病有重要价值,能量多普勒(或高清显像)易产生彩色溢出,极易将左无名动脉与动脉导管的交叉关系误认为解剖上的连接,将本畸形误诊为双主动脉弓.结论 镜像右位主动脉弓形成血管环在胎儿期并非少见,由于胎儿期粗大的动脉导管开放,极易将交叉走形并无连接的左无名动脉与降主动脉误判为解剖连接,从而形成双主动脉弓的诊断,正确诊断本病的关键是对无名动脉的走形及其与降主动脉和导管的关系进行多切面的扫查.

abstractsObjective To improve the prenatal echocardiographic diagnostic accuracy for fetus with isolated mirror-image right aortic arch which combined with vascular ring by analyzing and accumulating its echocardiographic features.Methods Echocardiographic signs were analyzed retrospectively and fetal echocardiographic features were accumulated in 16 cases with prenatal diagnosis of isolated mirror-image right aortic arch with left-side ductus arteriosus which formed vascular ring between January 2014 and February 2016.All cases were confirmed by neonatal echocardiography.Results The fetal echocardiography characters:① In 3-vessel and trachea view,fetal right aortic arch was demonstrated a Ushaped appearance of the great vessels,the right arm of the ‘ U’ represented the aortic arch and its left branch with ductal continuation.② In 3-vessel and trachea view or upper axial mediastinal transverse view,left innominate artery passed straightly to the left of the trachea.Left innominate artery and right-side ductus arteriosus were overlapped and the distance of two vessels was very close.③ In double arch view and longitudinal view for ductus,Left innominate artery did not connect to descending aorta or ductus arteriosus and did not involve in the formation of vascular ring.④ Color Doppler played an important role in diagnosis of this disease.Power Doppler or high-definition imaging easily showed color overflow and wrongly displayed the crossed relationship of left innominate artery with descending aorta as the anatomical connection,and caused the misdiagnosis of this disease as double aortic arch.Conclusions Isolated mirrorimage right aortic arch with vascular ring is not rare in the fetal period.Because ductus arteriosus is large and patent during the prenatal period,it is easily mistaken for the crossed relationship of left innominate artery with descending aorta as the anatomical connection and finally misdiagnoses this anomaly as double aortic arch.The keys to accurate diagnosis of the disease are clearly visualization of the innominate artery and its relationship with descending aorta and ductus arteriosus by scanning different views.