[princessmarisa]

The subject of studying x-rays is called radiology I think.

It is normally part of medical departments in Universities.

So try searching for that instead.

Can your friend post here themselves?

I presume if they want to do a masters in something in England that they have a good standard of English so we might be able to explain and understand better.

I also am not sure that you would be able to study such a specialist subject in Japan, that is taught using English. You would probably have to go to a University in an English speaking country.