When I was going through the full body scan at the airport I fly through--it is a small one by the way-- I found out what the scans look like because of something I wore. My advice is not to wear anything with a metallic fibre in the threads. The scan picks up on them and bounces patterns all over the scan. The scan shows only a basic outline of the human form, but the sparkles from my sweater were amazing. My hip replacement didn't show up, but the sweater did, even when we put a jacket over it to hide it. --So I got patted down again, with apologies.