Simple transposition of the great arteries (TGA) is a cyanotic heart disease that accounts for 5% to 7% of all congenital heart diseases. It is commonly underdiagnosed in utero, with prenatal detection rates of less than 50%. Simple TGA is characterized by ventriculoarterial discordance, atrioventricular concordance, and a parallel relationship of TGA. The prenatal diagnosis of TGA influences postnatal outcomes and therefore requires planned delivery and perinatal management. For these reasons, it is important to identify the key ultrasound markers of TGA to improve the prenatal diagnosis and consequently provide perinatal assistance. The presence of two vessels instead of three in the three-vessel tracheal view, a parallel course of TGA, and identification of the origin of each of TGA are the key markers for diagnosing TGA. In addition to the classical ultrasound signs, other two-dimensional ultrasound markers such as an abnormal right convexity of the aorta, an I-shaped aorta, and the "boomerang sign" may also be used to diagnose TGA in the prenatal period. When accessible, an automatic approach using four-dimensional technologies such as spatio-temporal image correlation and sonographically-based volume computer-aided analysis may improve the prenatal diagnosis of TGA. This study aimed to review the ultrasound markers that can be used in the antenatal diagnosis of TGA, with a focus on the tools used by ultrasonographers, the obstetric and fetal medicine team, and perinatal cardiologists to improve the diagnosis of this condition.

This pictorial review describes the assessment of a great variety of types of congenital heart disease by three-dimensional ultrasonography with spatiotemporal image correlation using HDlive and the HDlive Flow silhouette rendering mode. These technologies provide fetal heart surface patterns by using a fixed virtual light source that propagates into the tissues, permitting a detailed reconstruction of the heart structures. In this scenario, ultrasound operators can freely select a better light source position to enhance the anatomical details of the fetal heart. HDlive and the HDlive Flow silhouette rendering mode improve depth perception and the resolution of anatomic cardiac details and blood vessel walls compared to standard two-dimensional ultrasonography.

Objective: To assess the mitral and tricuspid annular plane systolic excursions (MAPSE and TAPSE, respectively) and cardiac output (CO) in fetuses of pregnant women with pregestational diabetes mellitus (DM) using spatio-temporal image correlation M-mode (STIC-M) and virtual organ computer-aided analysis (VOCAL). Methods: This study was prospective and cross-sectional. It included 45 fetuses each from mothers with pregestational DM and healthy mothers, with gestation ages ranging from 20 to 36.6 weeks. The fetal cardiac volumes were obtained and analyzed by STIC and VOCAL methods. MAPSE and TAPSE were measured by STIC-M in the apical or basal fourchamber view. The values of the right (RV) and left ventricular (LV) CO were calculated by STIC and VOCAL. Results: The median values of TAPSE were 6.1 and 6.2 mm in the diabetic and control groups (P<0.001), respectively. The median values of MAPSE were 4.6 mm in the fetuses of mothers with diabetes and 4.8 mm in fetuses of healthy mothers. The fetal LV CO (60.4 L/min vs. 71.1 L/min; P=0.033, respectively) and RV CO (65.2 vs. 70.1 L/min; P=0.026, respectively) were lower in the pregestational DM group than in the control group. A significant effect of pregestational DM was observed in all functional parameters after adjusting, with fetal heart rate as covariant. There was moderate significant positive correlation between MAPSE and LV CO (r=0.53; P=0.0001) and between TAPSE and RV CO (r=0.46; P=0.0001). Conclusion Significant difference in functional parameters (TAPSE, MAPSE and LV CO) obtained by STIC and VOCAL were observed in the fetuses of the pregestational DM group compared to those of the control group.

Objective: To assess the mitral and tricuspid annular plane systolic excursions (MAPSE and TAPSE, respectively) and cardiac output (CO) in fetuses of pregnant women with pregestational diabetes mellitus (DM) using spatio-temporal image correlation M-mode (STIC-M) and virtual organ computer-aided analysis (VOCAL). Methods: This study was prospective and cross-sectional. It included 45 fetuses each from mothers with pregestational DM and healthy mothers, with gestation ages ranging from 20 to 36.6 weeks. The fetal cardiac volumes were obtained and analyzed by STIC and VOCAL methods. MAPSE and TAPSE were measured by STIC-M in the apical or basal fourchamber view. The values of the right (RV) and left ventricular (LV) CO were calculated by STIC and VOCAL. Results: The median values of TAPSE were 6.1 and 6.2 mm in the diabetic and control groups (P<0.001), respectively. The median values of MAPSE were 4.6 mm in the fetuses of mothers with diabetes and 4.8 mm in fetuses of healthy mothers. The fetal LV CO (60.4 L/min vs. 71.1 L/min; P=0.033, respectively) and RV CO (65.2 vs. 70.1 L/min; P=0.026, respectively) were lower in the pregestational DM group than in the control group. A significant effect of pregestational DM was observed in all functional parameters after adjusting, with fetal heart rate as covariant. There was moderate significant positive correlation between MAPSE and LV CO (r=0.53; P=0.0001) and between TAPSE and RV CO (r=0.46; P=0.0001). Conclusion Significant difference in functional parameters (TAPSE, MAPSE and LV CO) obtained by STIC and VOCAL were observed in the fetuses of the pregestational DM group compared to those of the control group.