Journal of Ultrasound in Medicine, Vol 10, Issue 5 277-280, Copyright © 1991 by American Institute of Ultrasound in Medicine
A comparative study of continuous- and pulsed-wave Doppler velocimetry in fetal and uteroplacental circulation
F. Y. Chan, T. C. Pun, C. P. Lee, C. Lam, J. Khoo and L. Leong
Department of Obstetrics & Gynecology, Queen Mary Hospital, University of Hong Kong.
Continuous-wave and pulsed-wave Doppler ultrasonography are the two common
methods used to study the fetal and uteroplacental circulation. We used
both methods in the same patient population in three different gestations
and in various fetal and uteroplacental vessels to compare the results from
both machines. Thirty-one normal patients were studied at 20, 28, and 36
weeks gestation. The results showed significant correlation with no
statistically significant differences between the two types of machines for
the peak systolic/end-diastolic ratios and resistance index for the
umbilical artery and uterine arteries. Significant differences, however,
were demonstrated when the arcuate artery was studied, or when the
pulsatility index was used for comparison. We therefore conclude that when
different machines are used for study, comparison of the results is only
valid for selected vessels and indices. Results for arcuate arteries and
pulsatility index should be compared with caution.
