What is a Myelogram?
A myelogram is an invasive diagnostic test that uses x-rays to examine the spinal canal. A special dye is injected into the spinal canal through a hollow needle. An x-ray fluoroscope then records the images formed by the dye. Myelograms can show conditions affecting the spinal cord and nerves within the spinal canal.
Causes for a Myelogram
Regular x-rays of the spine are only able to give a clear picture of bones. The dye used in a myelogram shows up white on the x-ray, allowing the doctor to view the spinal cord, exiting nerves, and canal in detail. The doctor inserts a hollow needle through the skin into the spinal canal. The dye is injected into the space surrounding the spinal cord and nerve roots. Then, x-rays and/or a CT scan are done. The scan can see in fine details and can tell your doctor how your bones are affecting your nerves.
A myelogram can detect conditions affecting the spinal cord, including:
- Disc herniations
- Bone spurs
- Spinal stenosis
- Tumors
- Infection
What To Expect During a Myelogram
Before surgery, your provider will perform a physical exam and review medical history. Certain medications will need to be discontinued prior to the procedure to prevent any interference, which your provider will advise you on. Drink as much fluid as possible up until midnight the day before your myelogram. Do not eat anything after midnight, unless you are diabetic, in which you may have different instructions. You will not be able to drive following the procedure, so arrange for a ride home.
You may be given a sedative to make you drowsy and relaxed. Next, a slender, hollow needle is inserted into your spinal canal to draw out some cerebrospinal fluid for testing. The contrast dye is then inserted into the spinal canal through the hollow needle.
After the dye is injected, you will lie on your stomach with a pillow under your abdomen. The table may be tilted to move the contrast dye through your spinal canal to take x-rays of your back. Be sure to remain very still. After the x-rays and CT scans have been taken, you will be taken back to be observed for 4-8 hours before being released.
What To Expect After a Myelogram
Following the procedure, stay in bed for 24 hours after your myelogram. Do NOT lie flat. Instead elevate the head of your bed and get up for short periods of time. Drink lots of fluids for 18 hours and if possible, drink caffeinated beverages which causes increased urination to eliminate the dye used. In general, you can resume normal activities the next day.
The radiologist will promptly review your images and communicate directly with your referring doctor.
Risk Factors for a Myelogram
A CT scan is safe for most people, although pregnant people should not have one. Be sure to let your doctor know if you are pregnant, have a history of allergies, diabetes, asthma, a heart condition, kidney, or thyroid problems.
About 5 to 10% of patients experience side effects caused by the dye, including:
- Headache
- Nausea
- Vomiting.
If your headache, nausea, or vomiting persists after 48 hours, contact your healthcare provider.