What is a myelogram?
A myelogram is an imaging procedure that examines the relationship between your vertebrae and discs, through your spinal cord, nerves and nerve roots. It determines whether there’s anything actively pressing against your spinal cord, nerves or nerve roots, causing pain in your back or numbness and weakness in your arms and/or legs. Before the test, a radiologist will inject a contrast medium (also called contrast material or dye) into your spinal canal through your lower back. Then, the radiologist may take a few X-rays of your spine (you can get more detailed information through a computed tomography (CT) scan of your spine after the injection). The dye will blend together with your spinal fluid, giving the surgeon or neurologist a clear look at the bones and soft tissues that might be causing your symptoms.
A myelogram test may be performed along with other spinal exams, such as a magnetic resonance imaging (MRI) test, a CT scan and regular spinal X-rays. Generally, if any of these tests don’t completely explain what’s causing your symptoms, or if your doctor needs additional information about the bones in your spine before making a decision about your treatment, they may suggest a myelogram and a post-myelogram CT scan.
When would your doctor recommend a myelogram?
If you have persistent back pain, your doctors will likely suggest either a CT scan or an MRI first. If both of these tests are unable to explain the problem, they may order a myelogram, as it can reveal certain problems that aren’t visible with a conventional CT scan or an MRI. A myelogram is particularly useful in terms of displaying a clearer picture of the bones, herniated discs and other soft tissues surrounding your spinal canal that may be compressing your nerves and/or spinal cord. There are times when your doctor will suggest a myelogram after a recent surgery, especially if you’ve developed any new, lingering pain or weakness as a result of the surgery.
What can you see from a myelogram?
A myelogram is able to show your spinal cord, spinal nerves, nerve roots, and bones in the spine by injecting contrast into your spinal fluid. As a result, it will also reveal whether anything is pressing against your spinal cord or nerves. There are a few different things that could be responsible for causing this pain and creating this unwanted pressure, including:
- Herniated or bulging discs.
- Arthritis in your spinal joints.
- Tumors within, or adjacent to, your spine.
- An infection, or other inflammatory processes.
Compared to an MRI, a myelogram, and the post myelogram CT scan, is able to show the bony details in a better way, but is less capable of showing the soft tissue details in your spine.
Notify your physician
Tell your physician about any medications you’re currently taking, including non-prescription drugs. Since this procedure requires placing a needle into your spinal canal, your doctors will be concerned about bleeding into or around your spine. They’ll be concerned if you are taking any medications that affect your ability to clot normally. You may need to stop taking any of the following medications both before (for 48 hours) and after (for 24 to 48 hours) your procedure:
- Dipyridamole (Persantine®) or warfarin (Coumadin®), as these medications can act as blood-thinners. Generally, you should stop taking these medications 4-5 days before your test.
You can still take your other medications, pending approval from your physician. If you take medications for high blood pressure, you may continue to do so.
Note: Do not stop taking any medication without first speaking with your primary physician, or without being requested to do so by your physician. If you have any of the following conditions, please notify your physician:
- Pregnancy or suspected pregnancy.
- Low platelets or another coagulopathy.
- Multiple myeloma, pheochromocytoma, homozygous sickle cell disease or a known thyroid disorder.
- Any drugs or food allergies.
- Any known reactions or allergies to contrast materials used during X-ray procedures.
Before the test
No lab work is required before a myelogram unless you have a history of bleeding problems or a specific condition, like dehydration or severe liver or kidney disease.
Before the test, please follow these guidelines:
For patients with diabetes
- Take your usual dose of insulin.
- When you arrive for your test, remember to remind your physician that you have diabetes.
Eating and drinking
Don’t eat or drink anything for six hours before your test. Hydration before a myelogram is very important; you should start drinking four to eight ounces of clear fluids every two hours the day before, and leading up to your test. Clear fluids are the only thing you’re permitted to consume in the six hours directly before your test. Examples of clear fluids include:
- Black coffee.
- Sugar water.
The day of the test
Please make transportation arrangements, as you should not be driving immediately after a myelogram.
Please do not bring any valuables such as jewelry or credit cards.
In your meeting with the radiologists before the procedure, they will ask you to provide verbal consent and both of you will discuss the different steps of the procedure, any questions you may have, and the anticipated risks, benefits and alternatives.
During the test
The radiologist and technologist will be in the room with you the whole time. They will ask you to lie on your stomach or side, on a tilting table, before beginning the procedure, which consists of:
- Cleaning your lower back with an antiseptic and giving you a local anesthetic.
- Once the area becomes numb, the radiologist will introduce a needle into your spinal canal and then inject a contrast material into the fluid-filled sac containing your spinal cord and nerve roots. This injection can sometimes create a sense of pressure, but this is generally resolved relatively quickly as you move around after the procedure. The needle will be removed once the radiologist has injected enough contrast material.
- Tilting the table slightly to ensure that the contrast material flows to the particular area of interest in your spine (the radiologist may also ask you to tilt or move your head).
- Taking limited preliminary X-rays of your spine once the contrast is in place, followed by a more complete CT scan of the region in your spine that your doctor believes is responsible for causing your symptoms.
This procedure typically takes about an hour and may cause some discomfort or a minor headache.
After the test
After you’ve completed your myelogram test, the radiologist will send you for a CT scan to better understand the cause of your symptoms. The radiologist will then send a detailed report to your personal physician. But directly after the myelogram, you will be monitored for one hour, after which a nurse will discuss your post-myelogram instructions. You will be given written instructions to follow once you get back home. Before leaving the hospital, you will be evaluated by the radiologist.
What are the risks of a myelogram?
Because this is an invasive procedure that requires the injection of a contrast material through a needle in your spine, there are some risks, including:
- Spinal fluid infection (meningitis).
- A spinal headache.
- Bleeding around your spine.
- An allergic reaction to the contrast material.
Results and Follow-Up
The days following the myelogram test
First, immediately notify your physician if you develop any of the following symptoms:
- Nausea and/or vomiting.
- A serious positional headache (this can be worse when you’re standing straight up).
- A fever.
- A stiff neck.
- Fluid leaking from the punctured area.
If you don’t have any of those symptoms, there are some things you can do following your procedure to help your recovery, including:
- Actively keep your head above the rest of your body. Try to remain flat on your back as much as you can.
- Drink lots of fluids and stay away from alcohol.
- Try Tylenol and caffeinated drinks to help with positional headaches, as these can help spontaneously relieve these symptoms.
- Don’t engage in any heavy lifting or strenuous physical activity for 24 hours.