Discography (also called a discogram) is a nonsurgical, diagnostic procedure used to determine if a disc is causing back pain. Discs are sponge-like cushions located between the bones of the spine, acting as a shock absorber for the spine and providing flexibility to the overall structure. When a disc ruptures, it may press on the nerve of the spinal column, causing pain and weakness.
During a discogram, a contract liquid is injected into the center of a disc using x-ray guidance. The injection consists of a dye, as well as antibiotics to prevent infection, and may temporarily induce back pain in the patient. The procedure lasts 30 to 45 minutes. After injection, the patient’s response is carefully noted. If the patient experiences pain after injection, then the disc may be the source of back and/or neck pain.
Discography involves the following mechanisms of action, which may lead to pain in an abnormal disc:
Increases intradiscal pressure
Biochemical or neurochemical stimulation
Increased pressure at the end plates
Transfer of pressure to an abnormal disc
A discogram should only be performed if conservative therapy and noninvasive diagnostic procedures, such as MRI, fail to reveal the source of back pain. Indications for a discogram include the following:
Persistent and severe pain
Recurrent disc herniations
Failure of other diagnostic tests