A discogram, or discography, is an interventional diagnostic imaging test that helps physicians identify the intervertebral disc causing back pain.
Intervertebral discs are sponge-like cushions located between the vertebrae, or bones, of the spine. Discs act as a shock absorber and support flexibility in the spine.
Each disc has a strong outer layer called an annulus and a nucleus made of a soft, rubber-like material. A bulging or ruptured discs may press on the nerves of the spinal column and cause pain or weakness.
A discography injection may temporarily reproduce the patient’s back pain symptoms and help the physician identify the exact source of pain. An x-ray or CT scan may also be done to obtain images of the injected disc.
A discogram is typically done to diagnose the cause of back pain and inform the treatment of abnormal discs. The procedure may also be done prior to surgery to help identify discs that require treatment or removal.
A nurse or technologist will insert an intravenous (IV) line into a vein in the patient’s hand or arm to deliver sedative medication intravenously. However, the patient will be awake during the procedure so that they can describe any of the symptoms they experience during the test.
The patient may also receive medications to help prevent nausea and pain, as well as antibiotics to help prevent infection. Monitors will be used to track the patient’s heart rate, blood pressure, oxygen level, and pulse throughout the entire procedure.
The treatment area will then be shaved, sterilized, and covered with a surgical area. Next, the doctor will numb the injection site with a local anesthetic and use an X-ray machine to insert a needle through the skin and into the center of the disc.
An X-ray machine produces a small burst of radiation and creates an image on photographic film or a special detector. The X-ray images will then be stored electronically in digital files.
Once the needle is inside the disc, the physician will release a dye and remove the needle. Patients will be asked to describe the location, distribution, and severity of the pain they experience during the procedure. The physician will repeat the process by injecting multiple other discs to ensure the test is objective. The patient will not be told at which level the dye is being injected.
Once the procedure is over, the physician will apply pressure to the injection site(s) to prevent bleeding and cover the skin with a bandage. Some patients may also need to undergo a CT scan to further analyze the injected disc(s). A nurse will remove the IV line and the patient will be free to go home once the sedative has worn off.
Discography is the use of imaging to direct an injection of dye into the center of one or more spinal discs to help identify the source of back pain. The procedure is also used to inform the treatment of abnormal intervertebral discs – sponge-like cushions located between the vertebrae of the spine.