Three and four dimensional ultrasound: a novel method for evaluating fetal cardiac anomalies.

OBJECTIVE: To evaluate the role of various new models of 3- and 4-dimensional (3D and 4D) ultrasound (US) applications in prenatal assessment of fetal cardiac anomalies.
METHODS: Volume data sets of 81 fetuses with fetal cardiac anomalies, as previously diagnosed by 2D US, were acquired by 3D and cine 4D using spatiotemporal image correlation (STIC) software. Various additional rendering tools were applied. Color, power, high definition Doppler and B-flow were added to the volumes acquired. A retrospective offline analysis of the cardiac defects was performed.
RESULTS: The mean gestational age at diagnosis was 24 weeks (range 13-38); 128 anomalies were detected and were classified into the following categories: I, Situs anomalies in 8 cases; II, abnormal four-chamber view in 63 cases; III, outflows tract anomalies in 27 cases; IV, arches anomalies in 21 cases; and V, veins anomalies in 9 cases. Rendering tools differed in each groups of anomalies.
CONCLUSIONS: Fetal cardiac anomalies can be evaluated adequately by the information gained by 3D and 4D volumes obtained by STIC. Since no single module is sufficiently accurate for the diagnosis of all cardiac anomalies, each of the cardiac anomaly categories requires different and appropriate module of visualization.