应用脉冲多普勒检测完全性大动脉转位胎儿大脑后动脉血流变化

Changes of blood flow in posterior cerebral artery in fetus with complete transposition of great arteries by pulsed Doppler ultrasound

目的应用脉冲多普勒检测分析完全性大动脉转位（CTGA）胎儿大脑后动脉（PCA）血流变化。方法应用脉冲多普勒检测20例CTGA胎儿（CTGA组）及20例正常胎儿（对照组）的PCA两个节段（S1和S2）和大脑中动脉（MCA）的血流指标，包括收缩期峰值流速（VS）、舒张末期流速（Vd）、搏动指数（PI）、阻力指数（RI）、速度时间积分（VTI）。比较CTGA胎儿和正常胎儿之间血流指标的差异，对比分析CTGA胎儿PCA和MCA之间的阻力异常率。结果与对照组相比，CTGA组MCA—PI、MCA—RI、PCAS1—PI、PCAS1-R1均明显减低（P〈0．05），MCAVTI、PCA-S1-VT1、PCA-S2-VTI均明最增高（P〈0．05），两组间Vs、Vd、PCA-S2-PI、PCA-S2-RI差异均无统计学意义（P〉0．05）。CTGA组PCA-S1阻力异常率明显高于MCA（P〈0．05）。结论应用脉冲多普勒检测分析CTAG胎儿PCA血流动力学，提示PCA血流动力学变化可出现区域性及节段性差异，在缺血缺氧时机体可能更倾向于保护PCA供应区域。

Objective To study the changes of blood flow in posterior cerebral artery （PCA） in complete transposition of great arteries （CTGA） through the application of the pulsed Doppler. Methods Twenty CTGA fetuses（CTGA group） and 20 healthy control fetuses （control group）were involved, the blood flow indexes peak systolic velocity （Vs）, end-diastolic velocity （Vd）, pulsatility index （PI）, resistance index （RI）, velocity time integral （VTI） of PCA SI, PCA-S2 and MCA of the fetuses in the two groups were detected by pulsed Doppler. The differences in blood flow indexes between CTGA fetuses and heahhy controls were analyzed by independent t -test. The rates of abnormal resistance in PCA S1 and MCA in CTGA fetuses were compared through Chi-square test （x^2 test）. Results Compared with control group, the MCA PI, MCA RI, PCA-S1-PI and PCA S1 RI of CTGA group decreased significantly（all P 〈0.05 ）, MCA VTI, PCA-S1-VT1, PCA-S2-VTI increased significantly （all P 〈0.（15）, but no significant difference was found in PCA S2-PI, PCA-S2-RI, Vs and Vd of the MCA and the PCA （all P 〉11.05）. The rate of abnormal resistance in the MCA was significantly lower than that in the PCA S1 in CTGA group （ P 〈0.05）. Conclusions The pulsed Doppler can be used to study the changes of blood flow in PCA of CTGA fetuses and the differences of specific hemodynamic alterations may occured in different segments of the PCA in CTGA fetuses, indicating a tendency to protect the PCA supplying areas of the brain when ischemia and hypoxia.