Ultrasound Dropout in in utero Detection of Septal Defects

Due to limited lateral resolution, an apical 4-chamber view of the heart may give the appearance of a ventricular or atrial septal defect if the septum is parallel to the ultrasound beam. A subcostal view should be obtained to determine if the VSD or ASD is real.

References

Chaoui R. Anomalies and Diseases of the Fetal Heart. In Eberhard Merz (Ed.), Ultrasound in obstetrics and gynecology. Georg Thieme Verlag. 2004.