3-DIMENSIONAL ULTRASONOGRAPHY OF NORMAL FETAL HEART - COMPARISON WITH2-DIMENSIONAL IMAGING

Thirty-one high-risk patients (16 to 35 weeks' gestation) underwent tw o-dimensional and three-dimensional ultrasonography to compare two-dim ensional and non-cardiac-gated three-dimensional ultrasonography of th e normal fetal heart. After normal two-dimensional studies, three-dime nsional sonographic volumes were acquired without cardiac gating in tr ansverse and longitudinal planes. Standard cardiac views were derived from three-dimensional data, analyzed, and rated as follows: (1) not i dentifiable, (2) identifiable but inadequate for diagnosis, (3) adequa te, and (4) excellent. Two-dimensional ultrasonography demonstrated be tter yields of diagnostically acceptable images of basic echocardiogra phic views (four-chamber view, 100% for two-dimensional sonography ver sus 10 to 71% for three-dimensional sonography; right ventricular outf low tract, 42% for two-dimensional versus 6 to 26% for three-dimension al ultrasonography; left ventricular outflow tract, 71% for two-dimens ional versus 13 to 45% for three-dimensional sonography). In one subje ct three-dimensional ultrasonography). was superior to two-dimensional sonography in demonstrating an outflow tract. Aortic and ductal arche s were not imaged with the two-dimensional technique but were availabl e from the acquired three-dimensional volumes in 3 to 32% and 23%, res pectively. False-positive and false-negative findings were observed on three-dimensional ultrasonograms. Overall, compared to two-dimensiona l ultrasonography, non-cardiac-gated three-dimensional sonography yiel ded inadequate reconstructed image quality of basic echocardiographic views (four-chamber view, right ventricular outflow tract, left ventri cular outflow tract). Three-dimensional ultrasonography, however, show s potential for allowing nonechocardiographers to acquire some diagnos tically acceptable views of the aortic and ductal arches.