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.