Lumbar spinal stenosis can usually be diagnosed based on your history of symptoms, a physical examination, and imaging tests.

Imaging tests that may be used to evaluate the condition of the spine include:

• Computed tomography (CT) scan of the spine, which is used to evaluate bones and joints.
• Magnetic resonance imaging of the spine (MRI), which shows the soft parts of the spine better than the bones. With spinal stenosis, the position of the spinal nerves and evaluation of the space available for them is easier to see on an MRI. Disc problems show up better on MRIs than on CT scans. MRI may also show tumors, infections, and other disorders.
• X-rays of the spine, which is used to measure the extent of arthritis or injuries to the vertebrae.
• Myelogram, which may detect narrowing of the spinal canal or abnormalities of the nerves branching off the canal. Myelography is rarely used to diagnose spinal stenosis.
• Bone scan, which is used to rule out cancer and other bone diseases.

Your health professional may try nonsurgical treatment, such as pain-relieving medications, exercise, and physical therapy, for a period of time before ordering imaging tests. If this treatment is effective, you may not need tests.

In some cases, the severity of symptoms may not relate to the degree of the narrowing of the spinal canal as seen on imaging tests. You may have very severe symptoms, but tests show relatively little narrowing of the spinal canal. Or you may have mild symptoms, but tests show a significant narrowing of the spinal canal. Therefore, treatment is based not only on imaging test results, but also on the severity of symptoms and their impact on your normal daily activities and quality of life.

Electromyogram and nerve conduction tests are sometimes done to see if you might have problems other than or in addition to Lumbar Spinal Stenosis. For example, these tests can help detect underlying nerve damage that sometimes develops in people with diabetes (neuropathy).