Evaluation of fetal foramen ovale blood flow by pulsed\xa0Doppler ultrasonography combined with spatiotemporal image correlation

Jiawei Zhou,Wenjuan Tang,Ganqiong Xu,Yuanchen Luo,Jianwen Yang,Shi Zeng

doi:10.1186/s12947-021-00247-0

Abstract

ObjectiveThe objective of this study was to determine fetal foramen ovale blood flow utilizing pulsed Doppler combined with spatiotemporal image correlation.MethodsA 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.ResultsGestational 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).ConclusionsThe 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.

Highlights

Shunting through the foramen ovale (FO), which constitutes the majority of left ventricular cardiac output (LVCO), is critical for the delivery of enriched oxygenated blood to the coronary circuit, cerebral circuit, and upper body of the fetus [1]
Our study identified gestational age-specific reference ranges for FO blood volume in normal fetuses from 20 to 40 weeks of gestation using Spatiotemporal image correlation (STIC) in rendering mode combined with pulsed Doppler
The findings of this study suggest that Absolute blood flow of foramen ovale (QFO) increases with advancing gestational age, showing an exponential increase from 20 to 30 weeks of gestation and a flat growth trend during the last trimester, while Weight-indexed foramen ovale blood volume (iQFO) decreases with advanced gestational weeks

Summary

Introduction

Shunting through the foramen ovale (FO), which constitutes the majority of left ventricular cardiac output (LVCO), is critical for the delivery of enriched oxygenated blood to the coronary circuit, cerebral circuit, and upper body of the fetus [1]. Indirect assessment of FO blood flow volume resulted in varied data due to different measurement methods for QP used by different authors. Spatiotemporal image correlation (STIC) software captures a fetal heart volume with a single automated sweep of the transducer in a limited time. STIC can produce more standardized imaging of the fetal heart and reduce operator dependency compared with conventional two-dimensional ultrasound (2DUS) [15]. Visualization of specific heart structures by surface rendering may provide an additional method for assessing cardiac morphology and function and has been used to calculate the area of many fetal cardiac structures, and these measurements present good intra- and inter-observer reproducibility [16,17,18,19]

Methods

Results

Discussion

Conclusion