Journal of Ultrasound in Medicine, Vol 17, Issue 10 649-660, Copyright © 1998 by American Institute of Ultrasound in Medicine
Three-dimensional ultrasonography of the fetal distal lower extremity: normal and abnormal
N. E. Budorick, D. H. Pretorius, D. D. Johnson, T. R. Nelson, M. K. Tartar and K. V. Lou
Department of Radiology, University of California, San Diego, USA.
The objective of this study was to compare two-dimensional and
three-dimensional ultrasonographic evaluation of fetal distal lower
extremities. Data from two-dimensional and three-dimensional
ultrasonographic examinations from 40 distal lower extremities in 33
fetuses from a predominantly high-risk patient population were compared.
Three-dimensional ultrasonography routinely provided three orthogonal
planes (coronal, sagittal, and axial) for distal lower extremity
evaluation. Specific features of distal lower extremity evaluation were not
different using two-dimensional and three-dimensional ultrasonography.
Rotation of the rendered volume provided assistance in assessing all but
one of 40 distal lower extremities. Time from image acquisition to
assessment for two views (coronal and sagittal) was longer with
three-dimensional ultrasonography (8.2 min) than with two-dimensional
ultrasonography (3.2 min). Confidence in the diagnosis of abnormal distal
lower extremities was slightly improved using three-dimensional
ultrasonography compared to two-dimensional ultrasonography. Pregnancy
management was assisted in three of the four cases with isolated limb
anomalies. In conclusion, three-dimensional ultrasonography improves the
ability to evaluate the fetal distal lower extremity because of the
multiplanar nature of volume assessment and the ability to rotate volume
data sets. In addition, it provides assistance in counseling families,
particularly for cases involving isolated limb anomalies.
