多普勒超声帧频对产前胎儿大脑中动脉测量的影响

Infulence of measurement of middle cerebral artery for prenatal fetus with improving Doppler ultrasound frame frequency

目的探讨提高多普勒超声帧频对测量胎儿大脑中动脉(MCA)收缩期峰值流速(PSV)和搏动指数(PI)的影响。方法应用彩色多普勒超声检测659例胎龄20~40周正常胎儿MCA的PSV和PI,第一次测量在常规设置下进行(测值分别为MCA.g-PSV和MCA.g-PI),第二次测量在优化设置提高帧频的条件下进行(测值分别为MCA.o-PSV和MCA.o-PI),比较两次测值的差异。采用线性回归分析PSV、PI与孕周的相关性,建立回归方程。结果优化设置后测得的MCA.o-PSV和MCA.o-PI均明显高于MCA.g-PSV和MCA.g-PI(均P<0.001),MCA.g-PSV、MCA.o-PSV与孕周均呈正相关(r=0.853、0.867,均P<0.001),回归方程分别为:MCA.g-PSV=2.104×孕周-23.452,MCA.o-PSV=2.298×孕周-25.283。≤孕28周时MCA.g-PI和MCA.o-PI均与孕周呈正相关(r=0.300、0.291,均P<0.001),回归方程分别为:MCA.g-PI=-0.050×孕周+0.435,MCA.o-PI=-0.048×孕周+0.519;>孕28周时MCA.g-PI和MCA.o-PI均与孕周呈负相关(r=-0.601、-0.517,均P<0.001),回归方程分别为:MCA.g-PI=-0.065×孕周+3.996,MCA.o-PI=-0.061×孕周+3.861。结论优化多普勒超声设置提高帧频可更准确地测量胎儿MCA的PSV和PI,对评估产前胎儿循环系统有重要价值。

Objective To explore the influence of measurement of middle cerebral artery(MCA)for prenatal fetus with improving Doppler ultrasound frame frequency.Methods A total of 659 normal fetal during 22~40 weeks were enrolled in this study.The parameters of blood flow including peak systolic velocity(PSV)and pulsatility index(PI)were measured and comapred between two equipment settings.The first measurement of MCA(MCA.g-PSV and MCA.g-PI)was performed under the routine setting of ultrasound equipment.The second measurement of MCA(MCA.o-PSV and MCA.g-PI)was performed under the condition of optimizing setting and increasing frame rate,the difference between the two measured values was compared.Linear regression was used to analyze the correlation between PSV,PI and gestational age,and a regression equation was established.Results The MCA.o-PSV and MCA.o-PI measured after optimization were significantly higher than MCA.g-PSV and MCA.g-PI with normal setting(both P<0.001).The MCA.g-PSV,MCA.o-PSV were positively correlated with gestational age(r=0.853,0.867,both P<0.001).The regression equations were MCA.g-PSV=2.104×gestational weeks-23.452 and MCA.o-PSV=2.298×gestational weeks-25.283,respectively.≤28 gestational week,MCA.g-PI and MCA.o-PI were positively correlated with gestational weeks(r=0.300,0.291,both P<0.001).The regression equations were MCA.g-PI=-0.050×gestational weeks+0.435,MCA.o-PI=-0.048×gestational weeks+0.519,respectively.>28 gestational week,MCA.g-PI and MCA.o-PI were negatively correlated with gestational weeks(r=-0.601,-0.517,both P<0.001).The regression equations were MCA.g-PI=-0.065×gestational weeks+3.996,MCA.o-PI=-0.061×gestational weeks+3.861,respectively.Conclusion Optimizing Doppler ultrasound settings and increasing frame rate can measure the PSV and PI values of fetal MCA blood flow parameters more accurately,which is of great value for prenatal fetal circulatory system evaluation.