Journal of Ultrasound in Medicine, Vol 16, Issue 12 799-805, Copyright © 1997 by American Institute of Ultrasound in Medicine
Birthweight prediction by three-dimensional ultrasonographic volumes of the fetal thigh and abdomen
W. Lee, C. H. Comstock, J. S. Kirk, R. S. Smith, J. W. Monck, R. Deenadayalu and P. J. Bendick
Department of Obstetrics and Gynecology, William Beaumont Hospital, Royal Oak, Michigan 48073, USA.
Our validation study examined a three-dimensional ultrasonographic phantom
that contained irregularly shaped volume targets ranging from 0.5 to 76.1
milliliters. Four different examiners made blinded measurements from volume
datasets that were acquired by 4 and 7 MHz transducers. Birthweight
predictions using abdominal and thigh volumes from 18 term fetuses also
were compared with two-dimensional ultrasonographic methods. In vitro
volume measurements were accurate, precise, and repeatable despite a small
systematic overestimation with increasing object size. Mean systematic
error and precision for birthweight predictions by three-dimensional
ultrasonography (-0.03% +/- 6.1%) were not significantly different from
those by two-dimensional ultrasonography (-0.60% +/- 8.8%). Conventional
prediction methods yielded three birthweights with greater than 15% error.
By comparison, except for one infant whose birthweight indicated an 11%
error, all predictions based on fetal volume parameters were within 10% of
true values. Accurate birthweight predictions by fetal volume parameters
appear to be technically feasible at term gestation although their
practical clinical application requires further investigation. Birthweight
predictions in this manner may allow remote consultants to evaluate the
fetus over wide-area computer networks despite the physical absence of the
patient.
