The ultrasound beam is swept up from the abdomen to the four-chamber view. The stomach and apex are on the same side of the fetus. The correct relationship of the aorta and inferior vena cava in the abdomen can be noted. The apical four-chamber view imaged here allows all the features that need to be checked in the normal four-chamber view to be seen.
The four-chamber view is seen in a lateral projection in which the fetus lies with the right anterior chest closest to the transducer. The ultrasound beam is perpendicular to the ventricular septum. All the normal features of a four-chamber view can be checked in this orientation, although the appearance of the four-chamber view is slightly different from the apical projection.
The ultrasound beam is swept up the front of the chest from the four-chamber view to image the left and right outflow tracts and transverse arch sequentially. The size and positional relationships of the great arteries can be checked. The normal crossover of the pulmonary artery over the aorta is demonstrated.
The transverse view of the duct and transverse arch are seen simultaneously on color-flow mapping. The longer vessel arising from near the front of the chest and directed straight back toward the spine is the pulmonary artery with its continuation as the arterial duct. The aorta arises in the middle of the thorax, forms the transverse arch on the right side of the pulmonary artery and duct, and crosses the midline to join the duct just to the left of the spine. In the normal fetus as shown here, these vessels should be of similar size and flow should be in the same direction within them.
The ductal and aortic arches are seen in the long axis of the fetus in slightly different planes of section. The transducer beam can be swept from the duct at the start of the clip to the aortic arch at the end. The normal size and positional arrangements of the great arteries can be noted.