Penile Ultrasound experience?

I have a question for the fellow guys here, has anyone of you ever received a penile ultrasound exam, and If so, for what reason, and what was it generally like? I have been wondering sometimes what it would be like to undergo this procedure, so I'm asking if any of you have had it.

@manofsound37 What kind of ultrasound do you mean? With or whitout erection? I had one without erection, the reason was an urological check-up. It was embarassing and also exciting, because it was the first for me, but not very different as other ultrasound exams.