Objectives: To explore whether the use of four dimensional (4D) ultrasound examination with B-flow imaging and spatiotemporal image correlation (STIC) can supply additional information with respect to two-dimensional (2D) gray-scale and color Doppler echocardiography in the prenatal characterization of isolated total anomalous pulmonary venous connection (TAPVC).
Methods: The study population comprised a group of three TAPVC fetuses that had been examined exclusively by conventional echocardiography, and a group of four additional cases initially identified by conventional echocardiography and examined further by 4D ultrasonography; a thorough postnatal work-up was available for all fetuses.
Results: At our center, isolated TAPVC was found in seven of 1040 fetuses with cardiac defects (0.67%). Anomalous drainage was supracardiac to the innominate vein in three cases, cardiac to the coronary sinus in two, and infracardiac to the portal vein in the remaining two cases. An evident asymmetry between left heart and right heart structures was observed in 4/7 cases. The confluence of the anomalous pulmonary veins (PVs) was visualized in 4/7 cases and the connecting vertical vein was identified in 3/5 cases at 2D echocardiography. 4D ultrasound imaging with B-flow imaging and STIC clearly visualized the anomalous PV confluence and the draining vertical vein in all four cases examined.
Conclusion: 2D and color Doppler echocardiography appears to diagnose reliably TAPVC, albeit with some limitations in thorough assessment of the pathology, depending on the anatomy of the defect, on the technical adequacy of the equipment used and on the experience of the operator. 4D ultrasound examination with B-flow imaging and STIC is apparently able to facilitate identification of the anatomical features of TAPVC, thus supplying additional information over that provided by 2D fetal sonography.