Conclusions
The ongoing diagnostic dilemma of CHDs being the most common group of malformations affecting fetuses and newborns and the varying detection rates of CHDs in the general population merits consideration as the prenatal screening for CHDs remains flawed16. The clinical relevance of this issue is obvious considering that an estimated 60 % of newborns with CHDs will require a corrective intervention throughout their lives. Fifty percent of affected newborns need an intervention in their first year of life, among whom two-thirds are characterized as being critical regarding short-term morbidity and mortality (20 % of all CHDs)20. Moreover, CHDs diagnosed postnatally result in greater costs merely related to emergency transportation of ill infants103. Despite the adoption of updated screening guidelines, the implementation of series of diagnostic planes to visualize cardiac anatomy, 2-dimensional echocardiography shows limitations related to image acquisition, angle dependency and, most strikingly, operator experience.
The advantages of 3D/4D echocardiography (STIC) over conventional 2D ultrasound in delineating cardiac anatomy have been clearly elaborated. Being less operator-dependent, it allows for more reproducible and objective echocardiographic assessment of the fetal cardiac morphology and function of all chambers and valves. However, a number of publications have argued that the additional value of 3D/4D US in the prenatal diagnosis of CHDs is rather limited and has only been reported in centers with high expertise as it requires extra time and effort1,104-106. Since the introduction of a semiautomatic technology (FINE), a standardized volumetric approach for cardiac anatomic assessment has become available to overcome the limitations of effective performance of fetal cardiac examination. FINE has recently been shown to enable cardiac evaluation in normal and CHD-affected fetuses with both high specificity and sensitivity6.
We demonstrated the superior value of this approach to comprehensively assess altered cardiac anatomy. It has previously been shown that the acquisition plane and insonation angle are crucial for both 2D image quality and proper volume computing107. It is of note and illustrated herein that the use of standardized procedures, namely, automatically realigned cardiac planes facilitate a systematic evaluation of the fetal heart virtually irrespective of fetal position. FINE provides the opportunity for even unexperienced operators to become familiar with the anatomy of the fetal heart and the spatial relationships of the heart structures. From our perspective, it seems logical as a next step that 4DUS with subsequent FINE application could be incorporated in daily practice in the future. However, using such technology to examine the fetal heart requires an important prerequisite, i.e., structured training interventions and feedback for sonologists to acquire high-quality volume data sets so that they are informative15,108,109.