Myelography is a diagnostic procedure based on contrasting the CSF spaces of the contents of the dural sac, as a result of which pathological formations, spinal cord deformities, mechanical obstacles, and blockages of the CSF pathways are detected.
The technical execution of the procedure is simple. To do this, a lumbar puncture is performed at the lumbar level of the spine (L3–L4 or L4–L5 vertebrae), after which a contrast agent is injected. The contrast in the image is formed by gas (oxygen, nitrous oxide) or X-ray contrast agents ("Amipak", "Dimerix", "Omnipak").
Today, a non-injectable method of performing myelography is already available. For MRI scans of the spinal cord, a special myelography mode is used. This allows us to assess the degree of filling of the subdural space of the spinal cord and its patency for the cerebrospinal fluid. The resulting image is three-dimensional and facilitates visualization and diagnosis of the lesion level for neurosurgeons.
Discography is a diagnostic procedure based on contrasting the intervertebral discs by injecting them with a water-soluble contrast agent.
At the cervical level, the discs are dotted in front. With knowledge of the anatomy and topography of neck formations, as well as with little practical skills, this procedure (discography) is easy to perform.
Discography at the lumbar level can be performed as well as lumbar puncture. The dura mater in discography is punctured twice when accessed at the lumbar level of the spine, which is not required at the cervical level.
In serial spondylography, images are taken simultaneously in two projections. The first — immediately after the introduction of contrast, and then with an interval of 1 s (5-6 images) and after the end of the introduction of contrast.
A more modern method of discography became available with the use of CT scanning. The contrast agent inserted into the disk allows you to see its full distribution from all sides. The resulting image of the discs, being three-dimensional, allows you to quickly assess the condition of the intervertebral discs in relation to the spinal canal and choose the most optimal method of treatment of the patient (conservative treatment or surgery).