A discogram is an interventional radiology procedure that can help your doctor evaluate back pain. Your back is made up of spinal disks comprised of a hard outer layer and a gel-like inner layer. These disks are the cushions between your vertebrae and your spine. If you have back pain, a discogram can help your doctor pinpoint which disks are causing the pain and whether or not they need to be removed. Cancer patients may have a discogram if they have been diagnosed with disc disease or back pain unrelated to cancer.
During a discogram, your doctor injects dye into the gel-like center of the disks that may be causing pain. The dye will show any cracks in the disk on an X-ray or CT scan.
Your doctor may give you a sedative intraveneously (through your vein) to help you relax during the test. While lying on a table, you may receive some numbing medicine to decrease pain from the discography needle. Your doctor will place the needle directly in the center of the disk using an imaging technique called a fluoroscopy. This technique ensures precision and accuracy during the test.
Once the dye is injected into the gel-like center of the disks, the dye will spread, allowing your doctor to see any cracks in the disk on an X-ray or CT scan. However, cracked disks alone may not be the reason for back pain. If a disk is damaged, you will usually feel some pain during the dye injection that is similar to the pain you feel daily, which is a better indicator of the source of pain.
Since a discogram is a more invasive test than an MRI or CT scan, it may not be used as an initial test for back pain.