Technical factors influencing sonographic visualization of fetal echogenic intracardiac foci

A fetal echogenic intracardiac focus (EIF) is most commonly a normal variant in a normal fetus, but owing to reports of an increased risk of aneuploidy with EIFs, the finding causes concern when noted on routine obstetric sonograms. This study was undertaken to determine which factors influence the sonographic visualization of fetal EIFs.

In part 1 of the study, records from 1,920 fetal sonographic examinations were reviewed for fetal age, indication for sonography, and abnormal findings. For all cases with EIFs recorded and 645 randomly selected cases with no record of EIFs, sonograms were reviewed for heart position at the time of the 4-chamber view, technologist performing the examination, fetal position, heart visibility, transducer frequency, machine type, amount of amniotic fluid, and presence/absence of an EIF. In part 2 of the study, machine settings were evaluated with respect to visualization of EIFs.

In part 1 of the study, only the technologist performing the examination and the fetal position were associated with visualization of EIFs. In part 2 of the study, we found that the standard obstetric mode settings are better for visualization of EIFs than are the fetal echocardiographic mode settings.

We conclude that technical factors influence visualization of EIFs.