Centro de Estudios Ultrasonográficos Perinatales (CEUSP). Valencia. Venezuela
Fetal cardiac examination is standardized using seven sonography views:
Four chambers view
Longitudinal left outflow tract
Short axis view for right outflow tract
Upper axial mediastinal three vessels view with tracheal location
Longitudinal view of aortic arch and pulmonary-ductus arch
Longitudinal view, for systemic veins and venous ductus.
Yoo et al.(1,2) was the first in suggested the "three vessel view" of the fetal upper mediastinum, which is a cross-sectional view of the major vessels in sequence: cava-aorta-pulmonary artery. The sagital view can be used too. In other hand Yagel et al.(3) proposed adding the trachea to "three vessel view" and created the three vessel and trachea view or vena cava-aortic arch-pulmonary artery and trachea view.
The three vessel and trachea view is the most cephalad transverse plane, located in the fetal upper mediastinum, is easily obtained once the four chambers view is adequately visualized, by moving the transducer cephalad and slightly obliquely from the four chambers view plane. A satisfactory three vessel and trachea view was define by Yagel et al.(3) as that witch demonstrate the main pulmonary trunk in direct communication with the ductus arteriosus, an to the right of the main pulmonary trunk, a transverse section of the aortic arch. A cross section of the superior vena cava was visualized to the left aortic arch, and posterior to it a cross section of the trachea. This view differs from the three-vessel view suggested by Yoo et al. in which the aortic arch and trachea were not included.
The normal V-shaped appearance of the major vessels, were the left arm of the "V" represents the main pulmonary artery and its left branch with ductal continuation. The aortic arch is the right arm of the "V" configuration. The trachea in this view should be located posterior and laterally to the vessel junction.
Abnormal aortic arch is defined when the ductus and aorta form a U-shaped configuration.
Achiron et al.(4) in his paper demonstrate that three vessel and trachea view can de useful in the diagnosis of some great-vessel pathologies: right aortic arch, double arch, vascular rings, interruption of the aortic arch, and others, because the hypoechoic trachea containing amniotic fluid may serve as a landmark in evaluation of the aortic arch position and orientation.