Have the patient lie completely flat without anything under the head. Ask them to lift their chin upward and look to the left. Then place the transducer in the suprasternal notch with the probe pointed at the left shoulder at about 2 o'clock. Sometimes you may need to tilt the probe to point downward.
Note that in this view the right pulmonary artery (arrow) courses underneath the arch, therefore we see it in a short axis view here.
It is often difficult to see all 3 major branches from the aortic arch. The descending aorta is also less well seen in the far field in this view.
An ideal suprasternal Long axis view
This view usually gives a nice look at the arch, from which the 3 major vessels may be seen to arise. The right pulmonary artery and brachiocephalic vein which empties into the SVC can also be seen. It is important to use color Doppler to assess flow in the ascending and descending aorta and then to use spectral Doppler as shown below.
Pulse wave Doppler in the ascending (left) and descending (right) aorta.
If there is an increase in the velocity of flow in the descending aorta (greater than 1.5 m/s) accompanied by flow turbulence on color Doppler imaging, then this may suggest the presence of aortic coarctation. CW Doppler should be used to assess for the maximal gradient.
An ideal Short axis axis view
If you rotate the probe clockwise 90 degrees you can show the aorta in short axis, the right PA in long axis and the left atrium sometimes with all 4 pulmonary veins. The color video shows the blue inflow from an upper pulmonary vein.