Objectives. The aim of this study was to establish nomograms for fetal stroke volume (SV), cardiac output (CO), and ejection fraction (EF) using four-dimensional ultrasound with spatio-temporal image correlation (STIC) modality. Methods. The fetal heart was scanned using STIC modality, starting with classic four-chamber view plane, during fetal quiescence with abdomen uppermost, at an angle of 20–30°, without color Doppler flow mapping. In post-processing virtual organ, computer-aided analysis technique was used to obtain a sequence of six sections of each ventricular volume in end-systolic volume (ESV) and end-diastolic volume (EDV). The SV (SV = EDV–ESV), CO (CO = SV × fetal heart rate), and EF (EF = SV/EDV) for each ventricle were then calculated. Intra- and interobserver agreement were then calculated. Results. Two hundred sixty-five fetuses, ranging in gestational age (GA) from 20 to 34⁺⁶ weeks, were included in the study. The left and right SV and CO increased exponentially with gestation and EF remained fairly stable through gestational. Mean left and right SV increased from 0.211 ml and 0.220 ml at 20 weeks to 1.925 ml and 2.043 ml, respectively, at 34 weeks. Mean left and right CO increased from 30.25 ml/min and 31.52 ml/min at 20 weeks to 268.49 ml/min and 287.80 ml/min, respectively, at 34 weeks. Both left and right mean EF remained constant at around 0.63 with advancing GA. Nomograms were created for LSV, RSV, LCO, RCO, LEF, and REF vs. gestational age. Intra- and interobserver agreement reached 95%. Conclusions. Four-dimensional ultrasound using STIC represents a simple and reproducible method for estimating fetal cardiac function. STIC seems to overcome many of the pitfalls of conventional ultrasound methods and has the potential to become the method of choice.

Technological innovations accompanying advances in medicine have given rise to the possibility of obtaining better-defined fetal images that assist in medical diagnosis and contribute toward genetic counseling offered to parents during the prenatal period. In this article, we show our innovative experience of diagnosing fetal malformations through correlating 3-dimensional ultrasonography, magnetic resonance imaging, and computed tomography, which are accurate techniques for fetal assessment, with a fetal image reconstruction technique to create physical fetal models.

The objective of this review was to demonstrate the main tools of three- and four-dimensional ultrasonography, using the spatiotemporal image correlation software and its respective applications for assessing the fetal heart and its vascular connections, along with its potential contribution towards screening for congenital heart diseases. Today, conventional, two-dimensional, echocardiography continues to be the gold standard for diagnosing congenital heart diseases. However, recent studies have demonstrated that spatiotemporal image correlation offers some advantages that boost two-dimensional accuracy in detecting congenital heart diseases, given that the fetal heart assessment can be completed in the absence of the patient (offline) and be discussed by different examiners. Additionally, data volumes can be sent for analysis in reference centers via internet links. Spatiotemporal image correlation also enables direct measurement of heart structures in rendering mode, such as the interventricular septum and the annulus of the atrioventricular valves. Furthermore, it enables assessment of cardiac function when used in association with the virtual organ computer-aided analysis software, thus making it possible to calculate the total systolic function, ejection fraction, and cardiac output.

Objective: To determine reference range for fetal interventricular septum area by means of 3-dimensional ultrasonography (3DUS) using the spatiotemporal image correlation (STIC) method. Methods: A prospective, cross-sectional study was conducted on 328 normal pregnant women between the 18th and 33rd gestational weeks. To obtain the interventricular septum area, a virtual plane was used, with the green line (region of interest) adjacent to the external margin of the septum, which was manually delimited. To evaluate the correlation of the septum area with the gestational age, different regression modes were evaluated. The intraclass correlation coefficient was used to evaluate the interobserver reproducibility. Results: The interventricular septum area showed correlation with the gestational age (r = 0.81). The mean increased from 0.47 ± 0.10 cm² in the 18th week to 2.42 ± 1.13 cm² in the 33rd week of gestation. The mathematical equation that best represented this correlation was provided by linear regression: interventricular septum area = 0.0511 × gestational age (R² = 0.095). The interobserver reproducibility was good, with bias of 0.01 cm², precision of 0.07 cm² and absolute limits of agreement of -0.14 and +0.15 cm². Conclusions: Reference range for fetal interventricular septum area were determined by means of 3DUS using STIC in the rendering mode and were shown to be reproducible.