The aorta is the main artery coming out of the right side of the heart and the "manifold" from which all freshly oxygenated blood is distributed to the body. The aorta is in the chest between the lungs, not in the abdomen.
That being said, my right thumb only goes as far as the fourth (ring) finger. The test with my left thumb is invalid as a table saw took half of that thumb 14 years ago.
After reading the article linked it is a test for an aneurysm of the ascending aorta, the part of the aorta that comes out of the heart to the arch. In my mind if it works for that it should be an indicator for the entire length of the aorta. While it can be detected with an echo (ultrasound) I would bet a lot of them are discovered as a serendipitous finding during a chest x-ray or possibly a CT. That is usually not something that is screened for. The parts of the aorta are the ascending aorta, the aortic arch, the descending aorta and the abdominal aorta (divided as above or below the kidneys).
An Abdominal Aortic Aneurysm (AAA) OTOH
is screened for. It is recommend all men and women age 65 to 75 get a one time screen which is done by ultrasound for this.
One thing you don't want to happen is to walk around with an undetected AAA and have it rupture. The odds of surviving that event are slim to none, even if already in the ER/hospital. The good thing, many are slow growing and can be managed very well often just by watching them to ensure they aren't growing excessively or by placing a graft inside your aorta either through an open procedure or through a catheter procedure that runs through your femoral artery to place a graft at the site of the AAA.
So the PSA for today, if you are 65 to 75 and have not been screened for a AAA it may be a good idea to get checked, it's quick, painless and could be a life saver.
bob
https://www.hopkinsmedicine.org/health/conditions-and-diseases/abdominal-aortic-aneurysm