Making a Back Pain Diagnosis: Imaging Tests - Magnetic Resonance Imaging (MRI)

X-Ray, CT Scan (CAT Scan), and MRI procedures are the most common medical tests used to diagnose the cause of back pain. Both the CT and X-Ray use radiation to collect images of the internal body structure, while the MRI uses a strong magnet to get detailed images of the body's soft tissues. Magnetic Resonance Imaging (MRI) images provide detailed, clear pictures of soft-tissue structures, such as ligaments and tendons, bone, blood vessels, cartilage, and muscles. This degree of image details allow doctors to see far more than just the bones, and space between the bones, unlike X-Ray images that are produce far less sophisticated images. When diagnosing back pain, this level of detail gives doctors the ability to confirm or rule out soft-tissue problem, which is good because back pain is more likely to be caused by muscular or soft tissue problems than to problems with the bones.

Magnetic Resonance Imaging (MRI) is a procedure in which a strong magnet (composed of large tesla coils) passes a force from one side of the machine, through the patient, and captures the images to produce a clear, detailed image of a cross section of the body. This process does not produce radiation, and is not thought to be harmful to the body. Though make a note that patient's with chronic medical condition should not make a habit of habitual medical radiologic testing, as some doctors and research studies point to possible harmful effects to constant exposure to radiation and strong magnetic fields.



MRI is often the radiologic tool of choice for detecting pressure on the spinal cord or pressure on the nerve roots exiting the spinal cord. MRI is also used for diagnosing infections of the spine and spinal tumors. MRI may also show certain forms of arthritis of the spine, including rheumatoid arthritis and ankylosing spondylitis. MRI may be successful at detecting the early forms of these two arthritic conditions, so that doctors may be able to treat these problems early before they cause severe degeneration of the cartilage.

There are two main types of MRI machines, closed MRI and open MRI. The closed MRI machine is similar to the CT Scan, as it involves a patient getting onto and lying down on a table that then slides into a tube that takes the 2-D and 3-D images of the bones and tissues. Patients with claustrophobia (fear of enclosed places) may have trouble with both of these closed style machines, as they may become fearful inside the narrow cylindrical space they must slide into for the technician to take the pictures. Open MRI scanners are usually much shorter and don't involve cylindrical tubes that patients have to lie still in for 30 minutes to 1 hour.

To perform a closed MRI, the technician may help you onto a narrow scanning table. Once the patient is on the table, the table is slid into the cylindrical tube of the MRI. This cylindrical space is a magnetic tunnel. the patient does not feel anything as a result of the test, though it may be difficult for some patients to lie still for so long in an enclosed space that is barely wider than their body.

The MRI procedure may be hazardous to any patient's with magnetic devices lodged or surgically implanted in their body, such as prosthetic joints, metal plates, partial or total joint replacements, or pacemakers. If you have any types of metal in your body, you should alert the technician or doctor doing the MRI procedure know, as you should not have this procedure.