At the time Roentgen wasn't really in the medical field, but he was a German physicist. What makes him special though is the fact that he found out how to harness the power of x rays, that alone is pretty major because we use x rays for lots of different important uses.
"Wilhelm Conrad Röntgen was a German physicist, who, on 8 November 1895, produced and detected electromagnetic radiation in a wavelength range known as X-rays or Röntgen rays, an achievement that earned him the first Nobel Prize in Physics in 1901."
His education was pretty great he went to University of Zurich, institute of Martinus Herman van Doorn (great because of higher than high school education!).
The invention of the X Rays was founded by this gentleman Mwahahahaha(evil scientific laugh), so next time you break a bone thank Roentgen for helping the doctors fix you up with his amazing invention!
All info was found in either the main thing google gives out, Wikipedia, and my favorite my brain summarizing or clarifying