RESUMO
OBJECTIVE: To assess (1) pulmonary artery and peripheral pulmonary blood flow by using a multigate spectral Doppler system and standard pulsed color Doppler ultrasonography and (2) the reproducibility of peripheral pulmonary artery blood flow velocity waveforms. METHODS: Thirty-three women were enrolled in the study Fetal pulmonary artery flow velocity waveforms were investigated by multigate spectral Doppler scanning and traditional pulsed Doppler ultrasonography plus color flow mapping. To establish the relationship between these 2 methods, we calculated the correlation coefficient, coefficient of variation, and limits of agreement. RESULTS: The 2 methods were not significantly correlated. The range of measurement agreement for these 2 methods suggests that there is a significant difference between the main and peripheral pulmonary artery blood flow, and the difference should be taken into account in the interpretation of Doppler flow velocity studies of the pulmonary artery. CONCLUSIONS: Multigate spectral Doppler scanning with power Doppler imaging may be a better way to assess the average flow impedance in a highly vascularized organ. This technique supplies a large number of Doppler signals in the region of interest and offers a quantified range of Doppler measurements, improving our understanding of fetal hemodynamics.