Magnetic Resonance Imaging (MRI scan) was developed in the 1980's and has revolutionized our ability to see normal and abnormal spinal structures and help diagnose what causes back pain. The MRI scan is an imaging test that allows physicians to assess a patient’s spinal anatomy and investigate an anatomical cause of the patient’s back pain. The physician will correlate the findings on the MRI scan with the patient’s signs and symptoms of back pain in order to arrive at a clinical diagnosis.
While the MRI scan represents a very sensitive and accurate assessment of spinal anatomy, it cannot distinguish between painful and non-painful structures in the spine. In fact, a patient may have severe back pain and an MRI scan that shows a relatively normal-looking spine, or conversely may have no back pain but the MRI scan reveals a lot of anatomical problems. Thus, the findings on MRI scans do not constitute a diagnosis and the MRI findings must be correlated with the patient’s physical exam and back pain symptoms to arrive at a clinical diagnosis.
It is not usually necessary to obtain an MRI scan at the initial onset of spine-related pain, as most cases of back pain will resolve within two to twelve weeks with proper conservative (non-surgical) treatment. Quite often, MRI scans are needed when conservative treatment is not working and more aggressive back pain treatments (e.g. injections or surgery) are contemplated to relieve the symptoms.
What An MRI Scan Reveals about Back Pain
When a physician orders an MRI scan, there is specific information that he or she is looking for. Information that is typically gleaned from MRI results include:
- Spinal alignment
- Disc height and hydration
- Vertebral body configuration
- Intervertebral disc - How does the disc appear? Is it normal, bulging, herniated, dehydrated or degenerated?
- Spinal canal size - Is it sufficient to comfortably accommodate the spinal cord and nerves? Is there spinal cord or nerve root compression?
- Nerves - Are the nerves “pinched” (compressed) or inflamed anywhere?
- Abnormalities - Are there any abnormalities near the spine that might simulate spinal pain?
- Spinal cord - Is the spinal cord normal in physical appearance?
- If post-surgery - Has anything changed since the spine surgery? Is there another disc herniation, postoperative scarring or infection?
Often, based on the patient’s medical history and physical exam, the treating physician will already have an idea of what he or she is looking for on the MRI scan results.