Marco - sorry I changed your post by placing a link to my instructions for converting an x-rays to digital format. Normally my website has the same information as Vicky's. If you can't find it, the index is a great place to look since I have over a 1000 pages on the website listed on Google along with 400 more for hip stories along with over 5000 for the Hip Talk Discussionn Group posts
http://www.surfacehippy.info/sitemap.php You can also do a Google search from the end of the right column.
When you convert the x-ray, make the largest horitzontal or verticle side about 600 pixels. Try not to make it too large or it won't send well.
Also most of the digital x-rays I get now all have a converting software with them if you put the disc into your computer and check it out.
You can also take real x-rays and hold them up to the window and take a digital photo of them. You need a light source and light from a window not in direct sun does work. That is how I took photos of my original x-rays in 2006.
If you wanted to send them via snail mail, just email Dr. De Smet and ask the correct address to use. He normally answers all his emails.
I hope that helps.
Pat