Helpme, you spelled it correctly. If you were diagnosed with ankylosing spondylitis/spondylosis (a very painful bone disease), you should continue on that track to confirm (or dispel) that diagnosis. An MRI with contrast is useful if one wants to look at specific organs, but in your case just a regular MRI should work to figure out exactly what is going on. I don't believe a rheumatologist or orthopedic surgeon would tell you you don't need an MRI. If you are in an HMO, sometimes the primary care doc is just trying to save money. They are discouraged from making specialist referrals and ordering expensive tests. It's a shame, but often times the bottom line is money when it comes to medical care. Do make it clear that you have had some symptoms since you were a child.
Hang in there and don't give up on getting proper care!