Four-dimensional ultrasonography of the fetal heart using a novel Tomographic Ultrasound Imaging display

Abstract

Objective: The objective of this study was to investigate the feasibility of examining the fetal heart with Tomographic Ultrasound Imaging (TUI) using four-dimensional (4D) volume datasets acquired with spatiotemporal image correlation (STIC).

Material and methods: One hundred and ninety-five fetuses underwent 4D ultrasonography (US) of the fetal heart with STIC. Volume datasets were acquired with B-mode (n=195) and color Doppler imaging (CDI) (n=168), and were reviewed offline using TUI, a new display modality that automatically slices 3D/4D volume datasets, providing simultaneous visualization of up to eight parallel planes in a single screen. Visualization rates for standard transverse planes used to examine the fetal heart were calculated and compared for volumes acquired with B-mode or CDI. Diagnoses by TUI were compared to postnatal diagnoses.

Results: (1) The four- and five-chamber views and the three-vessel and trachea view were visualized in 97.4% (190/195), 88.2% (172/195), and 79.5% (142/195), respectively, of the volume datasets acquired with B-mode; (2) these views were visualized in 98.2% (165/168), 97.0% (163/168), and 83.6% (145/168), respectively, of the volume datasets acquired with CDI; (3) CDI contributed additional diagnostic information to 12.5% (21/168), 14.2% (24/168) and 10.1% (17/168) of the four- and five-chamber and the three-vessel and trachea views; (4) cardiac anomalies other than isolated ventricular septal defects were identified by TUI in 16 of 195 fetuses (8.2%) and, among these, CDI provided additional diagnostic information in 5 (31.3%); (5) the sensitivity, specificity, positive- and negative-predictive values of TUI to diagnose congenital heart disease in cases where both B-mode and CDI volume datasets were acquired prenatally were 92.9%, 98.8%, 92.9% and 98.8%, respectively.

Conclusion: Standard transverse planes commonly used to examine the fetal heart can be automatically displayed with TUI in the majority of fetuses undergoing 4D US with STIC. Due to the retrospective nature of this study, the results should be interpreted with caution and independently confirmed before this methodology is introduced into clinical practice.

Figure 1

Tomographic Ultrasound Imaging of a normal fetal heart in systole (A) and diastole (B). The overview image on the left upper panel of each figure shows the orthogonal sagittal plane to the sections that are being displayed. Each line represents a slice. The center slice is marked with an asterisk (*) and each subsequent plane to the right or left is marked with numbers ranging from −4 to +4. The plane marked by the dotted line is not displayed. In this volume dataset, the five transverse planes of section proposed by Yagel et al. (Ultrasound Obstet Gynecol 2001;17:367–369) for the examination of the fetal heart are visualized. Please note that the five chamber view was better visualized during systole. Legends: PA: pulmonary artery; Ao: aorta; SVC: superior vena cava; LPA: left pulmonary artery; RV: right ventricle; LV: left ventricle; RA: right atrium; LA: left atrium; FO: foramen ovale; IVC: inferior vena cava; IVS: interventricular septum; 4CH: four-chamber; 5CH: five-chamber.

Figure 2

Tomographic Ultrasound Imaging (TUI) of a normal fetal heart in systole (A) and diastole (B). The volume datasets were acquired using B-mode and color Doppler imaging. The overview image on the left upper panel of each figure shows the orthogonal sagittal plane to the sections that are being displayed. Each line represents a slice. The center slice is marked with an asterisk (*) and each subsequent plane to the right or left are marked with numbers ranging from −4 to +4. The plane marked by the dotted line is not displayed. In this volume dataset, the three planes of section proposed by Chaoui et al. (Ultrasound Obstet Gynecol 2003;21:81–93) for the examination of the fetal heart are visualized.. Legends: PA: pulmonary artery; Ao: aorta; RV: right ventricle; LV: left ventricle; IVS: interventricular septum; 4CH: four-chamber; 5CH: five-chamber.

Figure 3

Tomographic Ultrasound Imaging of a fetus with coarctation of the aorta. A) Volume dataset acquired with B-mode: (1) the three-vessel and trachea view shows a narrow transverse section of the aortic arch; (2) the four-chamber view shows disproportion between the right and left ventricles. B) Volume dataset acquired with color Doppler: (1) the three vessel view confirms the narrow transverse aortic arch and shows aliasing; (2) disproportion between the right and left ventricles is confirmed in the 4-chamber view. Legends: PA = pulmonary artery; Ao = aorta; RV = right ventricle; LV = left ventricle; 3V = three vessel; 3VT = three-vessel and trachea; 4CH = four-chamber; 5CH = five-chamber; Trv = transverse.

Figure 4

Tomographic Ultrasound Imaging of a fetus with hypoplastic left heart syndrome, double outlet right ventricle and transposition of the great arteries. A) Volume dataset acquired with B-mode: (1) the three-vessel and trachea view shows the aorta leaving the right ventricle; (2) the five-chamber view shows the pulmonary artery leaving the right ventricle as well; (3) the four-chamber view shows the right ventricle and atrium only – the left ventricle is not visualized; 4) the transverse view of the fetal abdomen shows that the stomach is located on the right. B) Bolume dataset acquired with color Doppler: (1) the three-vessel view confirms that the aorta leaves the right ventricle; (2) the five-chamber view shows the pulmonary artery leaving the right ventricle as well. Legends: PA = pulmonary artery; Ao = aorta; RV = right ventricle; LV = left ventricle; 3V = three vessel; 3VT = three-vessel and trachea; 4CH = four-chamber; 5CH = five-chamber; Trv = transverse.

Figure 5

Tomographic Ultrasound Imaging in a fetus with pulmonary atresia. A) Systole. (1) In the three-vessel view, retrograde perfusion (in red) of a narrow pulmonary artery is observed; (2) severe tricuspid regurgitation is observed in the four-chamber view. B) Diastole: (1) the 5-chamber view shows the aorta connecting normally to the left ventricle; (2) the four-chamber view shows normal ventricular filling only on the left ventricle, with tricuspid regurgitation still observed in blue. Legends: PA = pulmonary artery; Ao = aorta; RV = right ventricle; LV = left ventricle; 3V = three vessel; 4CH = four-chamber; 5CH = five-chamber; Trv = transverse; TR: tricuspid regurgitation.

Figure 6

Tomographic Ultrasound Imaging in a fetus with transposition of the great arteries. A) B-mode imaging. (1) In the three-vessel and trachea view, only the aorta is visualized, leaving the right ventricle; (2) the five chamber view demonstrates a vessel that bifurcates (pulmonary artery) connected to the left ventricle; (3) the four-chamber view is normal. B) Color Doppler imaging. (1) the three vessel view shows the aorta connecting to the right ventricle; (2) the pulmonary artery leaves the left ventricle and bifurcates. Legends: PA = pulmonary artery; Ao = aorta; RV = right ventricle; LV = left ventricle; 3V = three vessel; 3VT = three-vessel and trachea; SVC = superior vena cava; 4CH = four-chamber; 5CH = five-chamber; Trv = transverse