Blood flow through the ductus venosus in human fetus : Calculation using Doppler velocimetry and computational findings

Color Doppler sonographic unit was used to study the ductus venosus (DV) flow in 26 normal fetuses between 20 and 36 wk of gestation. Maximal velocity flow tracings and vessel diameters were obtained at the isthmic and the outlet portion of the DV. Time-averaged velocities in the DV were measured from the recorded tracings. The velocity distribution in the two cross-sectional areas of the DV was evaluated using computational model simulations and the velocity shape coefficients were calculated as a function of vessel geometry. These values can be used to convert maximal Doppler velocities into mean spatial velocities for each fetus.