A myelogram is a procedure used to diagnose changes in or to the spinal cord. A dye that can be visualized on radiographs (x-rays) is sterilely injected into the space around the spinal cord where the CSF is located. The dye mixes with the CSF and outlines the spinal cord so that it can be visualized when a radiograph is taken. A Myelogram is used most commonly to diagnose intervertebral disc disease (IVDD), but can also show changes to the spinal cord when cancer is present. This requires general anesthesia and is usually only performed if it is being used to diagnose a problem that is going to be followed up with surgery to fix it.