Description

The probe is positioned in a complete sagittal fashion along the left border of the sternum, with the marker pointing towards the head. The probe is angled side to side to bring the duct (if present) into view. Angling the beam too much towards the left (by angling the probe towards the right) will bring the aortic arch into display. In the absence of the PDA, the pulmonary artery is seen above the descending aorta. Both vessels will have blue flow as blood flows away from the probe.