Conventional myelography is performed after a lumbar puncture by injection of contrast medium into the cerebro-spinal fluid which surrounds the spinal cord. Please note that the contrast medium is not injected into the spinal cord itself! By tilting the patient who is lying on the x-ray examination table, the contrast medium is shifted upwards or downwards along the spinal cord and the lumbar nerve roots. In this way, compressions or expansions of the cord and nerves caused by prolapsed intervertebral discs, spinal canal stenoses, tumors or cysts can be imaged. Due to the superior tissue contrast and non-invasive character of CT and MRT, indications for myelography nowadays are rare and are limited to cases with equivocal imaging findings.
Conventional myelography is specially indicated in symptoms brought on by certain movements or weight stress put on the vertebral column as in segmental instability (spondylolisthesis), mobile disc protrusions or spinal canal stenosis. Even then, myelography is usually followed by a so-called myelo-CT which profits from the high contrast resolution of the cerebro-spinal fluid after injection of contrast medium. In addition, the cerebro-spinal fluid is examined for content of proteins and cells.
Severe complications after myelography such as paralysis are extremely rare and up to now have never occurred in Mainz. One side effect may be low-pressure headache due to loss of cerebro-spinal fluid after lumbar puncture in 10 to 20% and in rare occasions transient nerve root irritation leading to segmental pain or sensations.