Fetal Echocardiography Practice Test

In a normal three-vessel/trachea view, the great vessels show a spiral, or serial, relationship. This reflects how the outflow tracts twist as they leave the heart: the pulmonary artery and the aorta are not merely side by side, but cross in a way that creates a gentle twist as they approach the mediastinum. Seeing this spiral arrangement in the 3VT view indicates the ventriculo-arterial connections are typical. If the vessels appeared parallel side-by-side, that would point toward a condition like transposition of the great arteries, which is not normal.