How can you measure aorta size?

Ultrasound: Ultrasound is the easiest, safest, and least expensive. Aorta size can also be measured with cross-sectional imaging, such as a ct scan or mr. Finally, we can measure aorta size during invasive angiography or heart catheterization.

Ultrasound, but...: The two primary ways we measure the aorta is by ultrasound or ct scanning. Each modality has its pros and cons. While ultrasound is the preferred screening and first-line method of aortic imaging, one caveat to keep in mind is that it does tend to overestimate the size of the abdominal aorta and it is not practical for imaging of the thoracic aorta. Ct is more accurate though not cost-effective.