A myelogram uses X-rays and a special dye called contrast material to make pictures of the bones and the fluid-filled space (subarachnoid space) between the bones in your spine (spinal canal). A myelogram may be done to find a tumor, an infection, problems with the spine such as a herniated disc, or narrowing of the spinal canal caused by arthritis.
The spinal canal holds the spinal cord, spinal nerve roots, and the subarachnoid space.
During the test, a dye is put into the subarachnoid space with a thin needle. The dye moves through the space so the nerve roots and spinal cord can be seen more clearly. Pictures may be taken before and after the dye is used. To get more information from the test, a CT scan is often done after the X-rays, while the dye is still in your body.
Why It Is Done
A myelogram is done to check for:
- The cause of arm or leg numbness, weakness, or pain.
- Narrowing of the spinal canal (spinal stenosis).
- A tumor or infection causing problems with the spinal cord or nerve roots.
- A spinal disc that has ruptured (herniated disc).
- Inflammation of the membrane that covers the brain and spinal cord.
- Problems with the blood vessels to the spine.
- A myelogram may help find the cause of pain that cannot be found by other tests, such as an MRI or a CT scan.
How To Prepare
Your doctor will tell you if you need to change how much you eat and drink before the myelogram. You may be asked to increase the amount of water you drink before the test. Follow the instructions exactly about eating and drinking, or your test may be canceled.
Before a myelogram, tell your doctor if you:
- Are taking any medicines. You may need to stop taking some medicines for 2 days before the test.
- Have epilepsy or a seizure problem.
- Are or might be pregnant.
- Are allergic to any medicines, contrast material, or iodine dye.
- Have bleeding problems or take blood-thinning medicines, such as aspirin, warfarin (Coumadin), or clopidogrel (Plavix).
- Have asthma.
- Have ever had a severe allergic reaction.
- Have had kidney problems.
- Have diabetes, especially if you take metformin (Glucophage).
- Arrange to have someone take you home and stay with you after the test.
Talk to your doctor about any concerns you have regarding the need for the test, its risks, or how it will be done.