What does a discogram show?
A discogram is used to evaluate a painful or degenerative disc. If the contrast dye spreads outside the center of the disc, it may indicate that the disc annulus has tears or has ruptured. The results of a discogram may confirm the need for surgery, as well as determine the exact cause of your back pain, which will increase the likelihood of a positive outcome from surgery
Discogram is an invasive diagnostic test that uses x-rays to examine the intervertebral discs of your spine. A special dye is injected into the injured disc or series of discs. The dye makes the disc visible on a fluoroscope monitor and x-ray film. Discograms are used to locate precisely which discs are damaged and are causing back pain.
How should I prepare for the test?
Do not eat any solid foods after midnight on the night before the test. Make arrangements to have someone drive you to and from the hospital. Come dressed comfortably in a warm-up suit, sweats or shorts. Please leave all jewelry and valuables at home. Before the test, you will be asked to change into a hospital gown and an intravenous (IV) line will be placed in your arm. The radiologist or nurse will discuss the test with you, explain the risks, answer any questions, and have you sign consent forms.
Tell your doctor about any medicine you take. You may need to stop taking certain pain medicines 7 to 10 days before the test because they can prevent your blood from clotting.
Try to relax. Although a discogram may be an uncomfortable procedure, it is usually over within 30 to 40 minutes.
What happens after the test?
You will be taken back to a room and observed for 30 minutes. Be sure to drink plenty of water or fluids to help clear the dye from your body. You will be allowed to go home that day. You should take it easy for 24 hours following the test. Some people experience headache after the test – don't take aspirin – take ibuprofen or Tylenol for relief.
How does a discogram work?
Regular x-rays of the spine only give a clear picture of bones, such as the vertebrae. Myelograms only give a clear picture of the spinal canal. Discograms, however, enable your doctor to view the disc itself. While viewing an x-ray monitor, called a fluoroscope, the doctor inserts the hollow needle through your skin into the center of the disc space. A fluoroscope machine, also called a C-arm, is an arc shaped piece of equipment that generates x-rays from one side and photographs them on the other side. Once the needle is in place, a dye (contrast agent) is injected into the disc that shows up white on the x-rays.
A discogram works in two ways—both to view your disc and to find the source of your pain. Your doctor injects the dye into your disc space to try to recreate the pain. If you feel pain, then that disc is the likely source of your pain. If you don't feel the same kind of pain—even if that disc appears degenerated on the MRI scan—then other possible causes of your pain should be explored.