The objective of this study was to determine fetal foramen ovale blood flow utilizing pulsed Doppler combined with spatiotemporal image correlation. A cross-sectional study was performed in 440 normal fetuses between 20 and 40 weeks of gestation. In order to calculate foramen ovale blood flow, the foramen ovale flow velocity–time integral was obtained by pulsed Doppler ultrasonography, and the foramen ovale area was measured by using spatiotemporal image correlation rendering mode. Foramen ovale blood flow was calculated as the product of the foramen ovale area and the velocity–time integral. Gestational age-specific reference ranges are given for the absolute blood flow (ml/min) of foramen ovale, showing an exponential increase from 20 to 30 weeks of gestation, and a flat growth trend during the last trimester, while the weight-indexed flow (ml/min/kg) of foramen ovale decreased significantly. The median weight-indexed foramen ovale blood flow was 320.82 ml/min/kg (mean 319.1 ml/min/kg; SD 106.33 ml/min/kg). The reference range for fetal foramen ovale blood flow was determined from 20 to 40 weeks of gestation. The present data show that the volume of foramen ovale blood flow might have a limited capacity to increase during the last trimester.

中文翻译：

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脉冲多普勒超声结合时空图像相关评估胎儿卵圆孔血流

本研究的目的是利用脉冲多普勒结合时空图像相关性来确定胎儿卵圆孔血流量。对 440 名妊娠 20 至 40 周之间的正常胎儿进行了横断面研究。为计算卵圆孔血流量，通过脉冲多普勒超声获得卵圆孔流速-时间积分，并采用时空图像相关渲染模式测量卵圆孔面积。卵圆孔血流量计算为卵圆孔面积与速度-时间积分的乘积。给出了卵圆孔绝对血流量 (ml/min) 的特定孕龄参考范围，显示从妊娠 20 周到 30 周呈指数增长，并且在最后三个月呈平稳增长趋势，而卵圆孔的体重指数流量（ml/min/kg）显着下降。中位体重指数卵圆孔血流量为 320.82 ml/min/kg（平均 319.1 ml/min/kg；SD 106.33 ml/min/kg）。胎儿卵圆孔血流量的参考范围是在妊娠 20 至 40 周期间确定的。目前的数据表明，卵圆孔血流量在最后三个月的增加能力可能有限。