What is myelography?

Myelography, also called a myelogram, is an imaging test that checks for problems in your spinal canal. The spinal canal contains your spinal cord, nerve roots, and the subarachnoid space. The subarachnoid space is a fluid-filled space between the spinal cord and the membrane that covers it.

A regular x-ray only shows your bones. So during a myelography, contrast dye is injected into the spinal canal. Contrast dye is a substance that makes specific organs, blood vessels, and tissue show up more clearly on an x-ray. This clear view of the bones, disks, and other tissues surrounding your spinal canal may help your health care provider find out if something is pressing on your nerves or spinal cord. This helps them choose the best treatment.

Myelography involves using one of these two imaging procedures:

• Fluoroscopy, a type of x-ray that shows internal tissues, structures, and organs moving in real time as a live video.
• CT scan (computerized tomography), a procedure that combines a series of x-ray images taken from different angles around your body.

Other names: myelogram

What is it used for?

Myelography is used to look for conditions and diseases that affect the nerves, blood vessels, and structures in the spinal canal. These can include:

• Herniated disk. Spinal disks are rubbery cushions (disks) that sit between the bones of your spine. A herniated disk is a condition in which the disk bulges out and presses on spinal nerves or the spinal cord.
• Tumors
• Spinal stenosis, which happens when the spaces in the spine narrow and create pressure on the spinal cord and nerve roots.
• Infections of the membranes and tissues of the spinal cord. This includes meningitis, which causes inflammation of the membranes.
• Arachnoiditis, a condition that causes inflammation of a membrane that covers the spinal cord

Your provider may also recommend myelography if you have new pain or weakness in your back after a recent surgery.

Why do I need myelography?

You may need this test if you have symptoms of a spinal disorder, such as:

• Pain in the back, neck, and/or leg
• Tingling sensations
• Weakness
• Trouble walking
• Trouble with tasks that involve small muscle groups, such as buttoning a shirt

What happens during myelography?

A myelography may be done at a radiology center or in the radiology department of a hospital. The procedure usually includes the following steps:

• You will need to remove any jewelry, removable dental appliances, eyeglasses, and any metal objects that may interfere with the x-ray.
• You may need to remove your clothing. If so, you will be given a hospital gown.
• You will lie on your side or stomach on a pillow or a padded x-ray table.
• Your provider will clean your back with an antiseptic solution (to kill the germs on your skin).
• You will be injected with numbing medicine so that you won't feel any pain during the procedure. Once the area is numb, your provider will use a thin needle to inject contrast dye into your spinal canal.
• You may feel some pressure when the needle goes in, but it should not hurt. The contrast dye may cause a warm or flushed feeling, nausea, or a metallic taste in your mouth.
• Your provider may remove a sample of spinal fluid (cerebrospinal fluid) for testing.
• You'll need to stay very still while the fluid is being withdrawn.
• Your x-ray table will be tilted in different directions to allow the contrast dye to move to different areas of your spinal cord. You will need to remain still so the images won't blur.
• Your provider will remove the needle.
• Your provider will capture and record images using fluoroscopy or a CT scan.

The procedure usually takes about an hour. Your provider may not receive your test results for a few days.

After the test, you may be monitored for one to two hours and will need someone to take you home. Your provider may ask you to:

• Rest at home with your head elevated (slightly raised) for a few hours.
• Avoid strenuous activity for one to two days after the test.
• Drink plenty of fluids.
• Avoid alcohol.
• Use an over-the-counter pain reliever if you have a headache.

Will I need to do anything to prepare for the test?

Your provider will let you know if there are any special instructions to follow. They may ask you to drink extra fluids the day before the test. On the day of the test, you will probably be asked not to eat or drink anything except clear fluids. These include water, clear broth, tea, and black coffee.

Tell your provider about any medicines you are taking. Certain medicines should not be taken before your test. These include aspirin and blood thinners. Your provider will let you know how long you need to avoid these medicines. It may be as long as 72 hours before the test. Don't stop taking any medicines unless your provider tells you to.

Are there any risks to the test?

You should not have this test if you are pregnant or think you may be pregnant. Radiation can be harmful to an developing baby.

For others, there is little risk to having this test. The radiation dose is very low and is not considered harmful for most people. But talk to your provider about all the x-rays you've had in the past. The risks from radiation exposure may be linked to the number of x-ray treatments you've had over time.

There is a small risk of an allergic reaction to the contrast dye. Tell your provider if you have any allergies, especially to shellfish or iodine, or if you've ever had a reaction to contrast material.

Other risks include headache and nausea and vomiting. The headache may last for up to 24 hours. Serious reactions are rare but may include seizures, infection, and a blockage in the spinal canal.

Contact your provider right away if you have any of the following:

• A headache that doesn’t go away in 24 hours 
• Fever
• A stiff neck
• Tingling or numbness in your legs
• Trouble going to the bathroom

What do the results mean?

If your results were not normal, it may mean you have one of the following conditions:

• Herniated disk
• Spinal stenosis
• Tumor
• Nerve injury
• Bone spurs
• Arachnoiditis (inflammation of the membrane surrounding the spinal cord)

A normal result means your spinal canal and structures were normal in size, position, and shape. Your provider may want to do more tests to find out what is causing your symptoms.

If you have questions about your results, talk to your provider. To understand the results of myelography, your provider may consider your symptoms, medical history, and the results of other tests.

Learn more about laboratory tests, reference ranges, and understanding results.

Is there anything else I need to know about myelography?

You may hear different names for the test, such as cervical or lumbar myelography. This is the same type of test. It only refers to the part of your spine that needs imaging.

MRI (magnetic resonance imaging) has often replaced the need for myelography. MRIs use a magnetic field and radio waves to create images of organs and structures inside the body. But myelography can be more useful in diagnosing some conditions, such as certain spinal tumors and spinal disk problems. It's also used for people who cannot have an MRI because they have metal or electronic devices in their bodies. These include a pacemaker, surgical screws, and cochlear implants.