Back Pain Home > Diagnosing Back Pain
- X-rays: Traditional x-rays use low levels of radiation to project a picture onto a piece of film (some newer x-rays use electronic imaging techniques). X-rays are often used to view the bones and bony structures in the body. Your doctor may order an x-ray if he or she suspects that you have a fracture or osteoarthritis or that your spine is not aligned properly.
- Magnetic resonance imaging (MRI): An MRI uses a strong magnetic force instead of radiation to create an image. Unlike an x-ray, which shows only bony structures, an MRI scan produces clear pictures of soft tissues, such as ligaments, tendons, and blood vessels. Your doctor may order an MRI scan if he or she suspects a problem, such as an infection, a tumor, inflammation, or pressure on a nerve.
In most cases, an MRI scan is not necessary during the early phases of low back pain unless your doctor identifies certain "red flags" in your history and physical exam. An MRI scan is needed if the pain persists more than three to six weeks, or if your doctor feels there may be a need for surgical consultation.
- Computed tomography (CT) scan: A CT scan allows your doctor to see spinal structures that cannot be seen on traditional x-rays. A CT scan is a three-dimensional image that a computer creates from a series of two-dimensional pictures that it takes of your back. Your doctor may order a CT scan to look for problems, including herniated discs, tumors, or spinal stenosis. (Click Spinal Stenosis for more information about this condition.)
- Blood tests: Although blood tests are not generally used to reveal the causes of back pain, your doctor may order them to get a complete blood count (CBC), which could point to problems such as infection or inflammation.
Your doctor may also order a blood test to get the erythrocyte sedimentation rate (also called sed rate), which will measure inflammation. Inflammation may suggest infection, some forms of arthritis, or, in rare cases, a tumor. (Click Causes of Back Pain for more information about potential sources of back pain.)