3-DIMENSIONAL ULTRASONOGRAPHY OF THE FETAL DISTAL LOWER-EXTREMITY - NORMAL AND ABNORMAL

The objective of this study was to compare two-dimensional and three-d imensional ultrasonographic evaluation of fetal distal lower extremiti es. Data from two-dimensional and three-dimensional ultrasonographic e xaminations from 40 distal lower extremities in 33 fetuses from a pred ominantly high-risk patient population were compared. Three-dimensiona l 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 th e rendered volume provided assistance in assessing all but one of 40 d istal lower extremities. Time from image acquisition to assessment for two views (coronal and sagittal) was longer with three-dimensional ul trasonography (8.2 min) than with two-dimensional ultrasonography (3.2 min). Confidence in the diagnosis of abnormal distal lower extremitie s was slightly improved using three-dimensional ultrasonography compar ed to two-dimensional ultrasonography. Pregnancy management was assist ed in three of the four cases with isolated limb anomalies. In conclus ion, three-dimensional ultrasonography improves the ability to evaluat e the fetal distal lower extremity because of the multiplanar nature o f volume assessment and the ability to rotate volume data sets. In add ition, it provides assistance in counseling families, particularly for cases involving isolated limb anomalies.