Dilated Aortic Root or artifact?

My husband recently had an echocardiogram to rule out valve leakage.  The echo showed no leaking valves, normal LV function, but dilated aortic root.  His cardiologist explained how these results could be an artifact, especially since there is no other heart disease, and my husband is only 46.  He is to have a CT scan to settle the question.  My questions are: How often do results like this turn out to be artifacts?  Is it usual for an echo technician to measure the aortic root incorrectly?  
Thank you for your time.
Bev

[Cleveland Clinic, MD]

As with any test there is a possiblity it could be wrong.  The measurement of the aortic root is not as percise with echo as with CT scan due to a number of technical factors.  I don't know exact percentages but proceeding to a CT or MRI scan is a reasonable next step.