Most people with injuries, very understandably, want to know what is causing their pain and hope that an imaging test of some sort will help them pin down the cause of their problem and provide a diagnosis.
For example, patients who come to see me at my Richmond Hill chiropractic clinic often ask if an x-ray is required. 95% of the time I will say "No".
This is because x-rays are very good at showing bony problems such as fractures and dislocations. So unless you've had a serious fall, accident or trauma of some sort, taking an x-ray is unlikely to show anything informative for your case.
X-rays could also show moderate to severe arthritic changes in the spine...but this is less likely unless you are older or have a history of putting your body through a lot of wear and tear through work or recreational activities. Plus, arthritis isn't always the primary cause of your pain even if it's visible on x-ray. At the end of the day, most 'garden variety' aches and pains are in fact, due to soft tissue/muscle problems and these can't be diagnosed on an x-ray.
MRIs are geared more towards assessing soft tissues (discs, ligaments, nerve roots, cartilage, muscle). However, they are costly and the typical waiting list can range from weeks to months. And MRIs typically just confirm the doctor's original diagnosis that was already made through a complete patient history and physical examination. Only in more severe cases does an x-ray or MRI actually lead you to more special care like surgery. For the most part, these tests will simply confirm that you do have tendonitis, an injured disc, swelling in the joint, arthritic changes, or sometimes, even that everything appears normal.
Either way, the next step is to simply follow through with a regular course of conservative care with your chiropractor, physiotherapist, massage therapist or trainer. If you simple follow through with their treatment recommendations you may find yourself already feeling great again before you even get that MRI appointment!