Myelogram is an imaging exam that uses contrast material to detect abnormalities with the spinal cord, spinal nerve roots, and spinal canal. Learn about how the test is performed, how doctors use the results, and the side effects of myelogram.
Definition
Myelography is an imaging examination that involves x-rays, imaging contrast, and the use of fluoroscopy. Injecting contrast material into the subarachnoid space allows radiologists to better view the spinal cord, meninges, and nerve roots. Because contrast is used, a very detailed picture of the spinal column is generated. The picture itself is called a myelogram.
Why the Test is Ordered
Myelography is ordered when a doctor suspects that a patient has a problem with the spinal cord, spinal nerve roots, or blood vessels that supply the spinal cord. These conditions can present with back pain, weakness, difficulty in making normal movements, or pain radiating from the back to the legs. The test can also be used to monitor conditions such as infection, tumors, spinal lessons, or inflammation of the membrane that covers the spinal cord.
Preparation
Little preparation is required for this test. Notify your doctor if you are taking any medications or if you are allergic to imaging contrast or barium. Your physician needs to know about your medications so that any medicine that could interfere with the test can be stopped a few days before your scheduled appointment. Blood thinners, antidepressants, and drugs used to treat diabetes must be stopped a few days before the test. Increasing your fluid intake at least one day before the test is important. If you think you may be pregnant, you must inform your doctor or the technologist performing the test.
Procedure
During the procedure, the patient is positioned facedown and a fluoroscope is used to visualize the spine. Once the doctor determines where to inject the contrast material, the injection site is cleaned and a local anesthetic is used to numb the area. The needle is inserted and advanced until it is within the subarachnoid space of the spinal canal. Contrast material is injected into the space and the needle is removed. Cleansing of the puncture site is done again to reduce the chances of post-procedure infection.
Once the contrast material has been injected, the x-ray table is tilted so that the contrast flows within the subarachnoid space and surrounds all of the areas being examined. X-ray images are taken and the patient may be repositioned one or more times. The patient is allowed to rest comfortably while the images are being reviewed. The test takes anywhere from 30 to 60 minutes and patients are usually observed for 1 to 2 hours after the test has been completed.
Side Effects
The side effects of myelogram can be mild or severe. Headache can occur when the patient stands or sits upright. Mild headaches may be relieved with rest and increased fluid intake, but more severe headaches may need to be treated by a physician. Another possible side effect is an adverse reaction to the contrast material. Symptoms of this type of reaction include rashes, sneezing, nausea, and itching. Other side effects include bleeding around the nerve roots or nerve injury due to the introduction of the needle into the spinal canal.
References
RadiologyInfo. "Myelography." Accessed 30 June 2009.