Vascular rings(VRs) are defined as congenital abnormalities of the aortic arch and its branches. The most common vascular rings include right aortic arch (RAA) and double aortic arches(DAA). Vascular rings can form a ring that may compress the esophagus and trachea ,which likely result feeding difficulties and respiratory distress. We have reported three cases about diagnosis of vascular rings using High-definition flow(HD-flow) render mode and spatiotemporal image correlation(STIC). In addition ,we have evaluated the postnatal imaging features of vascular rings.

Objectives: To investigate the incidence of single umbilical artery (SUA), malformation, and postpartum outcomes in a retrospective analysis of 781 fetuses with SUA. Methods: A retrospective analysis of 781 pregnant women with singleton fetuses with SUA were diagnosed in the Gansu Provincial Maternal and Child-care Hospital from 2013 to 2019. Detailed data on maternal and fetal characteristics and postpartum outcomes were obtained. Results: A total of 624 (79.9%) fetuses were diagnosed with isolated SUA, whereas 157 (20.1%) fetuses had SUA with other structural and/or chromosomal abnormalities. The highest incidence of malformations was found in the urinary system, followed by the cardiovascular system and the digestive system. The incidence of SUA on the right side was 59.1% and life side was 40.9% respectively. Fetuses with SUA and other abnormalities showed a trend to be small for gestational age (3061 g vs 3201 g, p < 0.01) but not be delivered preterm. Conclusions: After a diagnosis of SUA, structural observation of the fetus is required. The urinary, cardiovascular, and digestive systems should be the focus of observation. If relevant malformations are found, genetic testing must be performed. With isolated SUA, it is recommended to dynamically monitor biological indicators to be alert for SGA, but genetic testing is not recommended.