The spine IS the central nervous system for everything below your head. Often a problem in the spine will be demonstrated in other areas, hips, knees, elbows, etc. The MRI is important in telling the Doc what is NOT the problem as much as it is in helping find the cause of the problem. I would have the MRI done if I were in your place. Other problems that you may have no symptoms of could be found as well... just my opinion...