Increasing the Detection Rate of Normal Fetal Cardiac Structures: A Real-Time Approach

The purpose of this study was to determine if acquiring real-time sweeps of the fetal heart would be a more effective method of identifying normal cardiac structures compared with using static images during routine second-trimester obstetric sonograms. Subjects were scanned using three different techniques. The static image acquisition (protocol A) included three images of the fetal heart. Protocol B used two gray-scale sweeps through the fetal heart. Protocol C acquired three color loops of the fetal heart. The sweeps demonstrated a complete normal cardiac assessment in 71% of studies, compared with the static image and color Doppler techniques that completed a normal cardiac assessment in only 39% of studies, respectively. The real-time technique detected four chambers, the left ventricular outflow tract (LVOT), the right ventricular outflow tract (RVOT), the LVOT/RVOT crossover, and size and axis of the heart with a greater frequency than the static images and color loops in all cases. In addition, the real-time technique was able to demonstrate the pulmonary veins in 56% of cases compared with 3.6% for static images. The color Doppler acquisition demonstrated blood flow through the atrial-ventricular and semilunar valves in 86% of cases.