Many patients request an MRI examination. An MRI is a non X-ray imaging test that can identify abnormalities in the spine which are not seen on plain x-rays. An x-ray can show bone and arthritis as well as fractures. MRIs however can show “soft tissues”. Specifically, in MRI can identify a pinched nerve or a herniated disc.
Why, then, doesn’t everyone who has back pain get an MRI? There are several reasons. If you have back pain, the chances are very good that the problem is not from a tumor, herniated disc, or pinched nerve. The vast majority of back injuries are muscle strains. Most of these injuries heal in about six weeks with conservative care including anti-inflammatories, modified activities, and physical therapy. An MRI for these injuries would not change the treatment or the recovery time, but certainly will add significant expense to your medical care.
An MRI is useful for patients who do not respond to conservative care . If you have had treatment for six weeks and are still very uncomfortable, then an MRI is a very appropriate next step to be sure that nothing more than a soft tissue injury is causing your pain. Treatment is dependent upon the underlying problem. Progressive weakness or numbness or tingling or pain in the leg, can indicate a pinched nerve/Herniated disc, something that an MRI would see. In this case, an MRI would be very useful.
An MRI will not change the course of an injury. An MRI is most useful to identify problems that do not resolve in the usual time course and to be sure that nothing else is causing continued symptoms which might be treated in a different fashion, for example, with injections or surgery or different medications.
Remember, an MRI is useful in many circumstances but it’s not necessary for all patients with pain. Fortunately, most of us will get better with conservative and nonoperative care.