Can i request an MRI scan?

cant be bothered to go into detail but basically i have widespread joint pain and the doctors don't know whats causing it, they have done 6 blood tests and an x ray all of which are fine. however i believe that it may be damage to the ligaments or tendons and not the joints themselves. the doctors seem reluctant to do anymore tests which is deeply frustrating as my my future career is at stake. can i request an mri?