Indeed, each center has it's own criteria with "how big" the aortic root is, but there is typically little variance between them. From the information that you provided, it would appear that your aortic root might be a slightly enlarged, but the good thing is that the doctor feels that it is stable and not growing. WHile it is not a normal finding per se, it is not cause for immediate alarm. This would consitute a more of a wait, watch, and see what happens scenario.
long,
thanks for the post.
Everything in nature exist on a bell curve. Interpretation of radiographic studies do not fully take this into account. We often see mild variations which might be due to habitus or inherited tendencies. The interpreter doesn't have you sitting in front of them so they can only state what is seen in the study. I would imagine that minimal dilation with no change in 5 years would constitute part of this variation. As for size, each institution will have their own reading criteria, I would discuss this with your physician.
good luck