Hi to everyone, what are the tests which a good expert of ED should prescribe?

[giancolo]

Hi to everyone, what are the tests which a good expert of ED should prescribe to a guy of 22 years old who suffers from a total ED? I know hormones and testosterone's tests, ultrasound with induced erection, echography to see if there are plaques, but in addition to them? Is there any test which can establish if any nerve is damaged?