Radiological texting: Discography

Diagnostic tests Medical history and physical examination Radiological texting Plain X-rays CT Scan (Computed Axial Tomography) Magnetic Resonance Imaging (MRI) Radionuclide imaging Discography Myelography Neurophysiological testing Blood tests Other diagnostic tests

What it is:

It consists of injecting a substance within the fibrous disc ring, at the nucleus pulposus. This substance ("contrast") does not permit X-rays to go through. Once the substance is injected a conventional X-ray is taken, showing contrast distribution inside the disc. In the case of disc fibrous ring fissure, the liquid fills it and the X-ray detects it.

What it allows:

Discography permits determining if the disc fibrous ring is intact or is fissured or ruptured. In those cases where back pain is due to a fibrous ring fissure, the contrast injection may cause patients their usual pain.

Risks:

Discography is usually painful. There is also a minimum risk of allergy to contrast media, as well as irritation or disc infection ("discitis").

Indications:

The existing recommendations based on scientific evidence do not advise the use of discography, since their guidelines only address acute pain (of less than 3 months) and discography should only be considered in chronic patients.

Nowadays, discography is used rather as a test for eliciting pain, to confirm that pain is due to disc fissure, rather than to visualize the fissure itself, since many of them cause no problems.

Its use is only recommended in those cases of suspicion of disc fissure as the cause of frequent and intense pain, which is resistant to treatment, so that surgery is being considered. In this latter case, discography is used to confirm the presence of fissure and, above all, to evaluate if the test triggers the pain usually felt by the patient, which suggests the presence of a disc fissure. In this case it might be wise to consider surgery.