How to differentiate epigastric pulsation between thin person and aortic aneurysm?

Imaging study: Sometimes the epigastric pulsation in a thin person can be impressive! but if there's concern that it might be an aneurysm, an abdominal ultrasound or ct should delineate this well.

Radiologic imaging: An experienced examiner might be able to tell the difference between epigastric pulsation & an abdominal aortic aneurysm, but the surefire way to tell is with radiologic imaging. Ultrasound, doppler ultrasound, ct scan, mri--any of these will tell you if you have an aneurysm.

Ultrasound: As was mentioned, there are many types of studies used to evaluate this but ultrasound is the easiest, quickest, cheapest way to evaluate this with no radiation exposure.