Discogram

Definition

A discogram, or diskogram, is a test used to evaluate back pain. A discogram may help your doctor determine if your back pain could be caused by an abnormal disk in your spine.

During a discogram, dye is injected under low pressure into the center of several of your spinal disks. Then an X-ray or CT scan is performed to see if the disks are damaged.

Because a discogram is an invasive procedure, it's typically reserved for patients whose back pain persists despite repeated attempts at treatment. Your doctor may use the results of a discogram to help determine a new treatment plan for your back pain or in preparation for spinal fusion surgery.

Why it's done

A discogram is a test used to help determine if a specific spinal disk is causing pain and requires treatment.

Your doctor may recommend a discogram if:

• Conservative treatment, such as medication, physical therapy or activity restrictions, fails to improve your back pain after four to six months, and more invasive treatment, such as surgery, may be needed.
• You're scheduled to have spinal fusion surgery and your doctor needs to identify the disks that are the source of your back pain, so they can be removed during the procedure.

Because it's an invasive test, a discogram isn't appropriate for an initial evaluation of back pain. In addition, because diskography cannot clearly discriminate between disk problems for which surgery may be helpful and problems for which surgery may have little effect or a negative effect, and due to the increased risk of complications over other diagnostic tests, some physicians don't use diskography even when back pain persists. Instead, they rely on other tests, such as MRI and CT scanning, to diagnose disk problems and guide treatment.

Risks

Discogram is generally a safe procedure. But as with any medical procedure, discogram carries a risk of complications.

Potential complications include:

• An infection of the space between disks (diskitis)
• Worsening of chronic back pain
• Headache
• Nausea
• Injury to blood vessels or nerves in and around the spine
• Allergic reaction to the dye

How you prepare

You may need to avoid eating and drinking for a certain amount of time before the procedure. Your doctor will give you specific instructions.

What you can expect

During discogram
Discogram is performed as an outpatient procedure in a clinic or hospital room that has imaging equipment, so your disks can be examined during the discogram. You are awake during a discogram, but your doctor may give you an intravenous (IV) sedative to help you relax. You may also receive antibiotics through the IV line to help prevent diskitis.

Before a discogram, you put on a hospital gown. During the procedure, you lie on a table on your side, rolled forward slightly. Pillows may be used to help you maintain your position and to keep you comfortable. After you're in the correct position:

• A member of the health care team cleans the injection site on your back with an antiseptic to sterilize the area.
• Your doctor may inject an anesthetic into your back to decrease pain caused by the needles used during a discogram.
• Guided by an imaging technique that allows viewing of your internal organs in motion (fluoroscopy), your doctor inserts a needle through your skin and muscle into the center of the disk to be examined.
• Alternatively, your doctor may use two needles, instead of one, with the first resting at the outer edge of the disk and the second smaller needle passing through the middle of the first, into the center of the disk.
• Once the needle is in place in the disk, a contrast dye is injected into the disk, and then the needle is removed.
• You will likely have some pain during this process. A member of your health care team will ask you to describe your pain. Typically, if a damaged disk is the source of your back pain, you feel pain during the injection that's similar to the back pain you have day-to-day. If a disk is normal, there's little pain during injection.
• The process is repeated for each disk that needs to be examined.

After all the disks have been injected with contrast dye and the needles removed, your doctor performs an X-ray or CT scan of the disks to see if the dye spreads. If the dye stays in the center of the disk, the disk is normal. If the dye spreads outside the center of the disk, it means the disk is damaged. It may have begun to rupture or it may have tears in its outer ring.

After discogram
After a discogram, you remain in the procedure room for approximately 30 minutes to one hour for observation. If you experience pain, tell a member of your health care team.

Because of the sedation, have someone else drive you home following a discogram. You may have some pain at the injection site for several hours after you go home. If the pain is severe, call your doctor right away.

Results

Your doctor will review the imaging exams performed during a discogram, along with the information you provided during the procedure about the pain you experienced. Both the images and your description of the pain are important to help determine if the disks examined are the source of your back pain. Your doctor will use this information to guide your ongoing treatment or prepare for surgery.

Because a disk can be damaged without causing pain, and because reports of pain during a discogram can vary widely — depending on your pain tolerance, your description of the pain and a variety of other factors — doctors usually don't rely on the results of a discogram alone to direct treatment. Typically, results of a discogram are combined with results of other tests, such as MRI or CT scanning and physical examination, when determining a treatment plan for back pain.