Final answer:
To assess for aortic dilation in TTE, you need to visualize the distal part of the aorta, which is approximately 5 cm from the left ventricle.
Step-by-step explanation:
To assess for aortic dilation in transthoracic echocardiography (TTE), you need to visualize the distal part of the aorta. Specifically, you should be able to see the initial portion of the aorta that rises superiorly from the left ventricle for a distance of approximately 5 cm. This distance allows for adequate assessment of the aorta and detection of any dilation or abnormality.