What is unfolding of aortic arch?

“Unfolding of the aortic arch” is a common age-related change seen on chest X-rays, meaning that the aorta lengthens, stiffens, and widens, causing it to curve out more, which looks like a broader shadow (mediastinal widening) and is often linked to normal aging, hypertension, and aortic calcification, but isn’t usually a problem unless it suggests a true aneurysm. Unfolding itself is often a benign sign of aging and arterial stiffness, not necessarily a disease. It is important not to confuse aortic unfolding with a true aortic aneurysm which is a bulge of a weakened spot, though both involve changes in the aorta. In essence, “aortic unfolding” describes the physical straightening and widening of the aortic arch due to aging and arterial stiffening, making it appear larger on imaging.