Journal of Ultrasound in Medicine, Vol 13, Issue 6 457-463, Copyright © 1994 by American Institute of Ultrasound in Medicine
Time-domain ultrasonography during pregnancy
W. Lee, P. Bendick, A. M. Best, N. Kozlowski, J. S. Kirk and C. H. Comstock
Department of Obstetrics and Gynecology, William Beaumont Hospital, Royal Oak, Michigan 48073.
Time-domain ultrasonography is an alternative to Doppler analysis of blood
flow direction and velocity. The technique uses timing information between
successive echo pulses to measure flow velocities directly through a color
display map. Volume flow quantification also can be achieved by combining
time-domain methods with M-mode ultrasonography. This report describes our
preliminary experiences with fetal vascular imaging by time-domain
ultrasonography, compares Doppler peak velocity correlation to time-domain
sonography, and examines the in vitro accuracy of time-domain sonography
combined with M-mode volume flow measurements. Excellent agreement was
found between peak Doppler velocity measurements and time-domain
ultrasonography for a variety of maternal and fetal vessels (N = 29). Close
volume-flow correlation was observed between a flow pump and time-domain
ultrasonography under constant and pulsatile conditions. Time-domain
ultrasonography appears to be a useful alternative to Doppler techniques
for imaging small fetal vessels and also may provide the basis for accurate
volume flow measurements during pregnancy.
