RESUMEN
OBJECTIVE@#To analyze the application of three-dimensional power Doppler sonography (3-DPDS) in evaluation of the superior mesenteric artery (SMA) and superior mesenteric vein (SMV) in second-trimester fetus.@*METHODS@#Three-dimensional volume probe was used to collect the 3-DPDS blood flow images in 50 normal fetuses of 22-24 weeks and 50 fetuses of 30-32 weeks, respectively. The characteristics of three-dimensional ultrasound were analyzed. The clinical and imaging data of 4 fetuses of 26-32 weeks with midgut volvulus were analyzed retrospectively.@*RESULTS@#The display rates of SMA and SMV were 93%in normal group by 3-DPDS and those in volvulus group were 4/4 and 3/4, respectively. The SMV trunk was parallel to and on the right side of the SMA in the normal group, while 3 cases in volvulus group showed the characteristic relationship of SMV swirling around SMA.@*CONCLUSIONS@#3-DPDS can be used to observe the spatial relationship of SMA and SMV visually in fetus during the second trimester and is of value to diagnose and predict the outcome of midgut volvulus.