Back Pain Health Center

What Affects the Test

Reasons you may not be able to have the test or why the results may not be helpful include:

• If you are pregnant. The X-rays may not be safe for the fetus.
• If you have had a test with barium contrast material in the past 4 days. Barium shows up on X-ray films and can make it hard to get a clear picture.
• If you can't remain still during the test. The pictures may not be clear.
• If you are very overweight. This can make it hard to see the details of the spinal X-ray.

What To Think About

• Sometimes your X-ray results may be different because you were tested at a different medical center or because earlier test results are not available to compare to the new test findings.
• The most common causes of low back pain, such as strained back muscles or ligaments, do not show up on a spinal X-ray.
• Other tests, such as a CT scan, an MRI, or a myelogram, provide more information about the spinal bones, joints, nerves, discs, muscles, and ligaments than a spinal X-ray. For more information, see the topics Computed Tomography (CT) Scan of the Spine, Magnetic Resonance Imaging (MRI) of the Spine, and Myelogram.
• Spinal X-rays have been used by some employers to screen healthy people for possible future back problems. But most health professionals do not believe that this is appropriate. If a potential employer wants you to have a spinal X-ray before you can start working, you may want first to discuss the matter with the employer and your doctor.