Stop worrying.
You can have the Xray done here in the UK (and only if immigration here ask for it).
Even a 'bad' result won't stop you getting into the country or staying here.
You'll just be asked to get any health condition treated.
Oh, and don't offer to show immigration here THAT Xray result of course !
Naturally it will be best to get yourself checked again after you've arrived here to make sure you ARE in good health !
