Three-dimensional ultrasonography of normal fetal heart: comparison with two-dimensional imaging.
Thirty-one high-risk patients (16 to 35 weeks' gestation) underwent two-dimensional and three-dimensional ultrasonography to compare two-dimensional and non-cardiac-gated three-dimensional ultrasonography of the normal fetal heart. After normal two-dimensional studies, three-dimensional sonographic volumes were acquired without cardiac gating in transverse and longitudinal planes. Standard cardiac views were derived from three-dimensional data, analyzed, and rated as follows: (1) not identifiable, (2) identifiable but inadequate for diagnosis, (3) adequate, and (4) excellent. Two-dimensional ultrasonography demonstrated better yields of diagnostically acceptable images of basic echocardiographic views (four-chamber view, 100% for two-dimensional sonography versus 10 to 71% for three-dimensional sonography; right ventricular outflow tract, 42% for two-dimensional versus 6 to 26% for three-dimensional ultrasonography; left ventricular outflow tract, 71% for two-dimensional versus 13 to 45% for three-dimensional sonography). In one subject three-dimensional ultrasonography was superior to two-dimensional sonography in demonstrating an outflow tract. Aortic and ductal arches were not imaged with the two-dimensional technique but were available from the acquired three-dimensional volumes in 3 to 32% and 23%, respectively. False-positive and false-negative findings were observed on three-dimensional ultrasonograms. Overall, compared to two-dimensional ultrasonography, non-cardiac-gated three-dimensional sonography yielded inadequate reconstructed image quality of basic echocardiographic views (four-chamber view, right ventricular outflow tract, left ventricular outflow tract). Three-dimensional ultrasonography, however, shows potential for allowing nonechocardiographers to acquire some diagnostically acceptable views of the aortic and ductal arches.