OC33.03: Early visualization of the fetal coronary arteries by four‐dimensional ultrasonography with B‐flow imaging and spatiotemporal image correlation (STIC)

Abstract

Oral communication abstractsnot change significantly with gestational age (Lines of regression: y = −0.007x + 61 and y = −0,12x + 65). Discussion: With these new techniques it is possible to assess the ejection fraction of the fetal heart. This may be valuable in the evaluation and monitoring of fetuses at risk and fetuses with congenital heart defects. Objectives: Coronary arteries of normal fetuses can be visualized by color Doppler after 31 weeks of gestation. Earlier visualization may be possible with more sensitive methods for detection of blood flow. B-flow imaging is a technology that allows angleindependent detection of weak blood reflectors from vessels and has been previously used for 4D reconstruction of the cardiac outflow tracts. In this study, we used B-flow imaging with STIC to evaluate the coronary circulation of normal fetuses during the second and third trimesters. Material and methods: 64 examinations were performed in 62 normal fetuses between 15 and 40 weeks. Volume datasets were acquired with B-flow imaging and STIC using transverse sweeps through the fetal thorax. B-flow settings during acquisition were: dynamic range 12, sensitivity 4 to 5, and persistence 2. Volume acquisitions lasted from 10 to 15 seconds. Acquisition angles ranged from 20 to 30 degrees. A thick-slice rendering technique encompassing the left ventricle and the ascending aorta was used to visualize the right and left coronary arteries, which were identified as they emerged from the aortic root. Two observers who were not involved in volume acquisition analyzed the volume datasets. The coronary arteries were considered present when there was agreement between the two observers. Results: At least one coronary artery was visualized in 60.9% of cases (39/64). The right and left coronary arteries were visualized in 50.0% (32/64) and 40.6% (26/64) of the cases, respectively. The left circumflex artery was visualized in 3.1% of cases (2/64). The earliest gestational age at which both coronary arteries could be observed was 19 weeks and 1 day. Conclusion: Four-dimensional ultrasound using B-flow imaging and STIC allows early visualization of the fetal coronary circulation, opening up the possibility of early diagnosis and characterization of developmental anomalies of the coronary arteries. included conventional two dimensional and three dimensional (2D, 3D) imaging supplemented by 3D XI. The screening method is the same as that used in conventional 3D imaging, but the images displayed are similar to CT or MRI. Results: 3D XI screening resulted in multiple slice views of 111 fetuses at full strength (normal views, n = 6; abnormal, n = 105). 3D XI presented sequential, sectional views of sagittal, coronal, and axial planes at the same time, similar to CT or MRI. In our experience, 3D XI was useful in volume measurement of lesions in the hypothyroidism and congenital cystic adenomatoid malformation, and accurate localization and mapping of the Dandy Walker variants, cleft lip and cleft palate and heart anomalies. Conclusions: 3D X...

An enhancement of coronary blood flow in a fetus with supraventricular tachycardia

“…While an increase in coronary blood flow in an anemic fetus is caused by a short-term autoregulation process operated by both neural and chemical factors, an augmentation of coronary blood flow in IUGR as evidenced by an earlier demonstration of coronary blood flow with an increase in both systolic and diastolic velocity is believed to result from a short-term autoregulation from myocardial hypoxemia superimposed on a longterm vascular remodeling and enhanced vascular reactivity resulting from chronic uteroplacental insufficiency (Barnea and Santamore, 1992;Baschat et al, 1997). Even though there have been reports more recently that visualization of coronary artery in normal fetuses could be appreciated at an earlier gestation, it is usually possible with a more sophisticated ultrasound technology such as B-flow imaging (Goncalves et al, 2005) or with a higher frequency transducer (Ji and Kwon, 2007). Using a conventional ultrasound in this case, an earlier manifestation of coronary perfusion at SVT and disappearance of the coronary flow on reversal of heart rate to normal sinus rhythm as well as an increase in both diastolic and systolic velocity during tachyarrhythmia may signify an enhancement of coronary perfusion in this specific condition.…”