Here is a copy of a letter I sent to a patient that summarizes the issues. He had just had a private MRI done because he was concerned about some recent low back ache, and then called me up to ask a) what I thought of the radiologist's report and b) should he have bothered having it done in the first place!
Peter, one point of MRI's for the spine is to find pathology (e.g. tumours or fractures) - icky stuff - there is no indication here of anything like that.
Another is to find evidence of significant, unexpectedly large (adjusted for your age) degenerative change in the spine; of the disc, the facet joints etc. Yours seems normal for age. We all get wear and tear in 50's and 60's.
Another is to find evidence of structural or developmental anomalies (e.g. you have an extra verterbra, or a missing x or y). No evidence of that.
Finally, the last point of the MR is to see evidence of something that is causing the pain. In the absence of pathology this is remarkably difficult to do. Perhaps the most reliable case is where the patient has sciatica, and the scan shows evidence of a nerve root being impinged or squashed. Providing the actual nerve root in the scan does correlate with the patient's symptoms, this gives surgeons some comfort if they are planning to operate.
But diffuse low back ache is often not caused by damage or wear and tear to structures per se, but is often muscular or inflammatory. Here the scan is unable to identify these causes of pain.
This is one reason why x-rays have been largely dropped for the routine evaluation of low back pain, and why (at least in the NHS) an MR scan was not indicated for your current problem.
So the pain needs dealing with not by docs or surgeons, but by exercise, strengthening of the low back muscles, good sleep, a good bed, avoidance of poor sitting posture, good control of inflammation in the body, good bowel movements (this is surprisingly important) etc.
For example, these exercises done daily are excellent.
Build up slow smooth and strong 15-20 reps per day. Perhaps done half morning half evening
Not straight out of bed, when your back is 'stiffer', but after it has had a chance to loosen up.
Make sure your first two reps are especially slow and good. Technique has to be top notch. Observe the video carefully.
Work up from 10 kg to max 15 kg. Every day!