A myelogram uses X-rays (fluoroscopy) and a special dye called contrast material to make pictures of bones and nerves of the spine (spinal canal).
The spinal canal contains the spinal cord and nerve roots surrounded by a fluid-filled space called the subarachnoid space. For a myelogram, the dye (which contains iodine) is put into the subarachnoid space. X-ray pictures are taken as the dye moves into different areas of the subarachnoid space.
A myelogram can be used to find:
- A blockage in the spinal canal that may be caused by a tumor or by a spinal disc that has ruptured (herniated).
- Inflammation of the membrane (arachnoid membrane) that covers the brain and spinal cord.
- Problems of the blood supply to the spinal cord.
- Problems of the spinal cord and the nerves that branch off from the spinal cord.