I am currently abroad in the UK. After receiving my visa I did not need any X-rays but I had to get a physical and a few shots. Shots included: meningitis, tuberculosis (TB), typhoid, and hepatitis A and B. Also, I highly suggest to get a flu shot.

This is upon my own experience but the immunizations required for entry into each country will vary, so you should consult the country you will be entering in. Or you can refer to this website, which provides up- to- date info.
http://wwwn.cdc.gov/travel/default.aspx