Definition of ascending aorta dimensions

My husband is 63 years old and he has a diameter of ascending aorta (first 3 cm of length that the ultrasound can visualize and measure)  of 4.47 cm. The first time he was diagnosed with a dilated aorta was 7 years ago when he went to the ER with a blood pressure 180-120. The CT scan of ascending, thoracic and abdominal aorta did not show any other abnormalities but the ultrasound showed a diameter of ascending aorta of 4.2 cm. His systolic pressure is now under 140-80 mm and he is routinely checking his heart with ultrasound. The diameter seems to be the same but I am wondering what is the age-related range of aortic dimensions and whether this dilatation is actually an aneurysm.

[kenkeith]

Generally, an enlarged aorta greater than 4.0 is considered an aneurism (aneurysm), and greater than 5.0 there is consideration to surgery.