An intimal flap in the aorta is a hallmark ultrasound finding of aortic dissection, which can present with tearing chest/abdominal pain and differential blood pressures between arms. The flap represents separation of the intimal and medial layers of the aortic wall.

According to Rumack’s Diagnostic Ultrasound:

“An intimal flap visualized within the aorta is diagnostic of an aortic dissection.”