Discography, or discogram, is a diagnostic tool used to determine the structural integrity of an intervertebral disc (or discs) and if a particular disc is responsible for the patient's back pain. Provocative Discography is a form of discography that replicates the patient's 'discogenic' pain. The term discogenic is defined as a pain syndrome characterized by local or radicular pain cause by nerve root compression.
The test is performed on an outpatient basis in a hospital or medical facility. A local anesthetic is used to numb the target area. Fluoroscopy, an imaging technique that projects an x-ray type picture onto a monitor, is used to guide the spinal needle into the suspect intervertebral disc. A radiopaque dye is then injected through the spinal needle into the nucleus (center) of the disc.
During the test, the dye pattern is evaluated for leaks occurring outside the intervertebral disc walls. At this time, the patient's symptoms (e.g. back pain, tingling sensation) may be replicated due to the pressure created by the dye injection (provocative discography).
Discography is indicated when a patient's symptoms are severe and persist despite conservative therapy, when the results of other diagnostic tests (e.g. MRI) prove inconclusive, and/or if a disc abnormality is suspected. The results of a discogram are used to confirm a diagnosis.
The patient should inform the referring physician if allergic to an IVP (intravenous pyelography) or other contrast dye. Adverse and allergic reactions include hives, swelling, and difficulty breathing. Fore knowledge of an allergy can often be controlled by pre-medicating.
Following discography, the patient should drink plenty of fluids (e.g. water, juice) to clear the dye from the body.