This patient with Marfan syndrome should undergo surveillance imaging annually. Dilation of the ascending aorta is a systemic feature of Marfan syndrome, and the most life-threatening complication of Marfan syndrome is aortic aneurysm, which can lead to an acute aortic syndrome (aortic dissection, rupture, or both). Accordingly, examination of the ascending aorta and heart valves is mandatory in patients with Marfan syndrome. The severity of aortic disease is in relation to the extent of aortic dilation, the length of the dilated segment, and the location of aortic involvement. Most patients with Marfan syndrome present with enlargement of the ascending aorta; therefore, serial examination is focused mainly on assessing this portion of aorta. American College of Cardiology Foundation/American Heart Association guidelines recommend follow-up imaging 6 months after diagnosis, with annual surveillance thereafter if the aortic root is less than 4.5 cm in diameter and otherwise stable. This threshold is lower than for patients with an aortic aneurysm due to other causes because of the tendency for complications in patients with Marfan syndrome with an aortic root diameter above this level. If the aortic root diameter is 4.5 cm or greater or if the aortic root diameter shows significant growth from baseline, more frequent imaging of the aorta should be considered.

Imaging of the aortic root in patients with Marfan syndrome is usually performed with transthoracic ultrasound because it is able to accurately evaluate this portion of the aorta and is noninvasive. However, for aneurysms above the aortic root, CT or MRI is preferred as they more accurately measure the aortic dimensions in that region.