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.