探讨胎儿超声心动图三血管气管（3VT）切面定量测量动脉导管弓与主动脉弓之间的距离与夹角在胎儿右位主动脉弓（RAA）诊断中的应用价值。

选取单纯RAA左位动脉导管胎儿52例作为研究组（RAA组），随机选取正常胎儿121例作为对照组，分别测量2组胎儿超声3VT切面上动脉导管弓与主动脉弓内径及两者之间的间距与夹角（AP角），将RAA组与对照组间的各超声测量参数进行统计学分析。

RAA组与对照组比较，动脉导管弓与主动脉弓之间间距增大［4.86（4.16~5.74）mm vs 1.59（1.38~1.76）mm］，AP角减小［（12.96±1.83）° vs（22.14±1.35）°］，差异均有统计学意义（Z=-10.416、P<0.05，t=32.481、P<0.05）；RAA组与对照组的动脉导管弓内径、主动脉弓内径、动脉导管弓/主动脉弓内径比值、主动脉内径、肺动脉内径、主动脉流速、肺动脉流速比较，差异均无统计学意义（P均>0.05）。2组的AP角、动脉导管弓/主动脉弓内径比值与孕周均无相关性（RRA组：r=0.148、0.029，P=0.294、0.818；对照组：r=0.060、0.108，P=0.514、0.180）。2组的动脉导管弓与主动脉弓间距、动脉导管弓内径、主动脉弓内径、主动脉内径、肺动脉内径、主动脉流速、肺动脉流速均与孕周呈线性正相关（P均<0.05）。

胎儿超声心动图3VT切面测量动脉导管弓与主动脉弓间距及夹角的方法简单可行，能够为胎儿RAA左位动脉导管的诊断提供更为准确的定量参考，具有一定的临床应用价值。

To evaluate the application value of quantification of the distance and angle between the ductal arch and aortic arch in the diagnosis of fetal right aortic arch (RAA).

Fifty-two fetuses with isolated RAA were selected as a study group (RAA group) and randomly paired with 120 normal cases as a control group. The diameter of the ductus arteriosus and the aortic arch as well as the distance and the angle (AP angle) between the two arches was measured on the three vessel views (3VT view). Statistical analysis was performed for comparison of each parameter between the two groups.

Compared with the control group, the distance between the ductus arteriosus and the aortic arch increased [4.86 (4.16~5.74) mm vs 1.59 (1.38~1.76) mm], and the AP angle decreased [(12.96±1.83)° vs (22.14±1.35)°] in the RAA group (Z=-10.416, P<0.05; t=32.481, P<0.05). There was no significant difference between the two groups in the values and ratios of the diameters between the ductus arteriosus and the aortic arch, diameters of the aorta and pulmonary artery, or blood flow velocities across the aortic valve and pulmonary valve (P>0.05). There were no correlations between the gestational age and the AP angle or the ratio of the diameter of the ductus arteriosus to the aortic arch (RAA group: r=0.148, 0.029, P=0.294, 0.818; control group: r=0.060, 0.108, P=0.514, 0.180), while the distance between the ductus arteriosus and the aortic arch, diameters of the ductus arteriosus and the aortic arch, diameters of the aorta and pulmonary artery, and blood flow velocities across the aortic valve and pulmonary valve were all linearly positively correlated with the gestational age (P<0.05).

Measurements of the distances and angles between the aortic arch and ductal arch in the 3VT view of fetal ultrasonocardiography are simple and feasible, which may have a supplementary role in the diagnosis of fetal RAA with left-sided ductus arteriosus.