Diagnosis of truncus arteriosus in first trimester of pregnancy using transvaginal four-dimensional color Doppler ultrasound

Abstract

We present our experience of using transvaginal three/four-dimensional (3D/4D) color Doppler with glass-body rendering mode and spatiotemporal image correlation (STIC) software to construct an image of persistent truncus arteriosus in the first trimester of pregnancy. There have been numerous reports on the antenatal diagnosis of truncus arteriosus using two-dimensional (2D) grayscale echocardiography, color Doppler and multiplanar display in 3D/4D ultrasound1-3; however, to the best of our knowledge, this is the first report on the antenatal diagnosis of truncus arteriosus using transvaginal 3D/4D color Doppler with glass-body rendering mode and STIC. A 37-year-old pregnant Japanese woman, gravida 8, para 2, was referred to our ultrasound clinic at 12 + 6 weeks of gestation because of suspected fetal hydrops and omphalocele. Transvaginal 2D sonography showed a single live fetus with biometry consistent with gestational age. A cystic hygroma was seen extending from the occipital part of the fetal head to the fetal back, associated with a giant omphalocele containing the liver, stomach and intestines. Detailed cardiac examination revealed the presence of ventricular septal defect (VSD) with a single arterial trunk giving rise to two branches (Figure 1a). 2D color Doppler revealed blood flow through the VSD, and demonstrated division of the truncus arteriosus into the pulmonary artery and aorta (Figure 1b). Transvaginal 3D/4D color Doppler with glass-body rendering mode and STIC (Voluson E10, GE Healthcare Japan, Tokyo, Japan) depicted clearly the truncus arteriosus straddling both ventricles and giving rise to the aorta and pulmonary artery (Figure 2 and Videoclip S1). The right pulmonary vessels and aortic arch, as well as descending aorta, were also distinguished. No other anomalies were detected and a diagnosis of truncus arteriosus with VSD was suggested. Unfortunately, the patient was lost to follow-up, resulting in no available data on the course of the pregnancy. The glass-body rendering mode depends on the simultaneous display of gray and color Doppler images, therefore, the crossing of the aorta and pulmonary artery, as well as ventricular filling, can be displayed in the same plane4. In the current case, transvaginal 2D fetal echocardiography demonstrated a single vessel overriding a VSD and color Doppler showed that the vessel divided into two branches. By 4D color Doppler with glass-body rendering and STIC, visualization of the pulmonary artery with right pulmonary vessels and the spatial relationships between the great arteries and branches were achieved easily. This is usually difficult with 2D Doppler but is key to a diagnosis of truncus arteriosus5. Applying this technique also helps to differentiate the pathology from pulmonary atresia with VSD as well as tetralogy of Fallot2. Moreover, the courses of the aortic arch and descending aorta were demonstrated clearly in the same scanning plane. This is beneficial in order to exclude the commonly associated interrupted aortic arch and to differentiate it from cases of aortic atresia with VSD1. In conclusion, we recommend the use of transvaginal 3D/4D color Doppler for the diagnosis of truncus arteriosus, as it facilitates diagnosis at an early gestational age. This work was supported by a Grant-in-Aid for scientific Research on Innovative Areas ‘Constructive Developmental Science’ (No. 24119004), and a research grant (No. 25462561) from The Ministry of Education, Culture, Sports, Science and Technology, Japan. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.