ABSTRACT
Doppler ultrasound has become an indispensable technique for fetal prenatal diagnosis,clinical monitoring,intrauterine treatment and assessment the timing of delivery nowadays.This study briefly described the principle of Doppler ultrasound and the structure of the fetus and placenta.Based on these,we discussed the application of Doppler ultrasound technique in diagnosing of fetal structural malformation,monitoring of significant blood vessels and screening of fetal chromosomal abnormality.
ABSTRACT
Objective To explore the correlations between measurements of Doppler velocity waveform parameters of fetal main pulmonary artery and gestation age (GA) in normal fetus. Methods This is a cross-sectional study, in which totally 252 normal singleton fetuses between 23 and 40 weeks of gestation were divided into 10 groups. The following velocity waveform parameters were measured in the main trunk of fetal pulmonary artery by Doppler ultrasound: acceleration time(AT), ejection time(ET), acceleration time/ejection time(AT/ET), peak systolic velocity(PSV), end diastolic velocity(EDV), mean velocity(MV), pulsatility index(PI) and resistance index(RI). The normal reference values of Doppler velocity waveform parameters at various GA were established. A scatter diagram of each parameter against GA was plotted out. The optimal formula was selected out according to the correlation and regression analysis. Results Among 252 normal fetuses, satisfactory Doppler velocity waveform of fetal main pulmonary were achieved in 249 (98.8%, 249/252). Among these parameters, AT, AT/ET, PSV, EDV and MV increased with increasing GA(F=343.23, 96.012, 8.649, 2.158, 10.169, all P0.05). Signiifcant and positive linear correlations were found between parameters of AT, AT/ET, PSV, EDV, MV and GA(r= 0.898, 0.868, 0.446, 0.203, 0.507, all P0.05). Conclusions The fetal main pulmonary artery could be a reliable sampling point to obtain pulmonary velocity waveform by Doppler ultrasound. Doppler velocity waveform parameters have correlations with GA in normal fetus;among which AT and AT/ET were the best.