Discogram, also known as a discography, is an interventional diagnostic imaging test. It can help determine whether a specific intervertebral disc is the cause of your back pain. Spinal discs are cushions between the bones of the spine. They are made up of cartilage and a jellylike substance. Their purpose is to act as shock absorbers between the bones in your spine.
A discogram is generally not used for the initial evaluation of back pain. But your doctor may suggest it if you continue to experience back pain, despite conservative treatments such as physical therapy and medication.
Sometimes a discogram is also used before a spinal fusion surgery, as it can help identify which disks require removal. However, it is noteworthy that a discogram is not always accurate in pinpointing which disk is leading to back pain. Therefore, many doctors prefer other tests, such as CT scan and MRI for diagnosing disk problems and guiding treatment.
Before the procedure, a blood test might be required to determine how well your kidneys are functioning and whether your blood clots normally. You will also need to inform your doctor about all the medications and supplements that you take. If you have an allergy to local anesthetic, general anesthesia, or to contrast materials, you should let him/her know about this as well.
Also, let your doctor know about any of your recent illnesses or any other medical conditions.
It is likely that you will be instructed not to consume any food or drink the midnight before the procedure. Your doctor will also let you know if it is okay to take any of your medications on the morning of the procedure.
You will need to arrange for someone to drive you home after the procedure.
First, you will need to change into a hospital gown. Then you will lie on a table, or on your side. After your skin is cleansed, your doctor will likely inject a numbing medicine to decrease the pain caused by the insertion of the discogram needle.
After this, your doctor will be using an imaging technique such as fluoroscopy, in order to watch the discogram needle enter the body. Fluoroscopy helps to allow more precise and safe placement of the needle into the center of the disk that needs to be examined. Then a contrast dye is injected into the disk, and then an X-ray or CT scan is taken to see if the dye spreads.
If the dye stays in the center of the disk, then the disk is normal. If it spreads outside the center of the disk, it indicates that your disk has undergone some wear-and-tear change. These changes may or may not be the cause of the pain.
In most cases, if the disk is the cause of your back pain, then you should feel pain during the injection, which is similar to the back pain that you normally experience daily. However, if the disk is normal, there is very little pain during the injection. You will also be asked to describe and rate your pain during the procedure.
After the procedure
After the procedure, you will be remaining in the room, for around 30-60 minutes so that you can be observed. After that, you are able to go home, but you will need someone to drive you.
It is not unusual to experience some pain at the injection site or in the lower back for several hours, after the procedure. You can apply an ice pack to the area for about 20 minutes, as this might help. You will also need to keep your back dry for 24 hours.
Within a week or two after the procedure, if you experience severe back pain or a fever, let your doctor know right away.
Your doctor will review the images and the information that you provided regarding the pain you experienced during the procedure, and this will help to pinpoint the source of your back pain. This information will be used by your doctor, to guide your treatment or prepare for the surgery.
Generally, doctors don’t rely on the results of a discogram alone as sometimes a disk with wear-and-tear might not cause any pain. Also, pain responses during a discogram may also vary widely.
Generally, results of a discogram are combined with results of other tests, like an MRI or a CT scan and physical examination, when determining a treatment plan for back pain.
Though it is most generally safe, a few risks of complications are associated with a discogram, which includes:
- Allergic reaction to the dye
- Worsening of chronic back pain
- Injury to nerves or blood vessels in and/or around the spine