Test Overview

A myelogram uses X-rays and a special dye called contrast material to make pictures of the
bones and the fluid-filled space (subarachnoid space) between the bones in your
spine (spinal canal). A myelogram may be done to find a tumor, an infection,
problems with the spine such as a
herniated disc, or narrowing of the spinal canal
caused by
arthritis.

The spinal canal holds the
spinal cord, spinal nerve roots, and the subarachnoid space.

During the test, a dye is put into
the subarachnoid space with a thin needle. The dye moves through the
space so the nerve roots and spinal cord can be seen more clearly.
Pictures may be taken before and after the dye is used. To get more information from the test, a
CT scan is often done after the X-rays, while the dye is still in your body.

Why It Is Done

A myelogram is done to check
for:

  • The cause of arm or leg numbness, weakness, or
    pain.
  • Narrowing of the spinal canal (spinal stenosis).
  • A tumor or infection causing problems with the
    spinal cord or nerve roots.
  • A spinal disc that has ruptured
    (herniated disc).
  • Inflammation of the membrane that covers the brain and spinal cord.
  • Problems with the blood
    vessels to the spine.

A myelogram may help find the cause of pain that cannot be
found by other tests, such as an
MRI or a CT scan.

How To Prepare

Your doctor will tell you if you need to change how much you eat and drink before the myelogram. You may be asked to increase the amount of water you drink before the test. Follow the instructions exactly about eating and drinking, or your test may be canceled.

Before a myelogram, tell your doctor if you:

  • Are taking any medicines. You may need to stop taking some medicines for several days before the test.
  • Have
    epilepsy or a
    seizure problem.
  • Are or might be
    pregnant.
  • Are allergic to any medicines, contrast material, or
    iodine dye.
  • Have had bleeding problems, or take a blood thinner, such as aspirin, clopidogrel (Plavix), or warfarin (Coumadin), or take over-the-counter medicines, such as ibuprofen (Advil, Motrin) or naproxen (Aleve). Your doctor will tell you when you should stop taking these medicines several days before your procedure. Make sure that you understand exactly what he or she wants you to do.
  • Have
    asthma.
  • Have ever had a severe allergic reaction.
  • Have had kidney
    problems.
  • Have
    diabetes, especially if you take metformin
    (Glucophage).

Arrange to have someone take you home and stay with you
after the test.

Talk
to your doctor about any concerns you have regarding the need for
the test, its risks, how it will be done, or what the results will mean. To help you understand the
importance of this test, fill out the
medical test information form (What is a PDF document?).

How It Is Done

The test is done by a doctor in
a radiology center or in the radiology department of a hospital.

You will need
to take off jewelry that might be in the way of the X-ray picture. You may need
to take off all or most of your clothes above the waist (you may be allowed to
keep on your underwear if it does not get in the way of the test). You will be
given a gown to wear during the test.

During the test

You will have a lumbar puncture to put the dye into your spinal
canal. You will lie on your stomach or side on an X-ray table. The doctor
cleans an area on your lower back. A numbing medicine is put into your skin.

After the area is numb,
a thin needle is put into the spinal canal and a stream of X-rays
(fluoroscopy) is used to help the doctor place the needle in the right area. A
sample of spinal canal fluid may be taken
before the dye is put in the canal.

After the dye is put in, you
will lie still while the X-ray pictures are taken.

After the
pictures are taken, a small bandage is put on your back where the needle
was put in. You will be told what to do after the test.

After the test

This test usually takes 30
minutes to 1 hour.

You may need to lie in bed with your head raised for 4 to 24 hours after the
test. This helps prevent or reduce side effects of the test, such as
headache, nausea, and vomiting. To prevent seizures, do not bend over or lie down with your head lower
than your body.

Avoid strenuous activity, such as running or heavy lifting, for at least 1 day after the test.

Drink plenty of water afterward. Your
doctor will give you instructions on taking your regular medicines.

How It Feels

You will feel a quick sting from the
small needle used to numb the skin on your back. You will feel some pressure as
the long, thin spinal needle is put into your spinal canal. You may feel a
quick sharp pain down your buttock or leg when the needle is moved in your
spine. You may find it hard to lie on your stomach or side during this
test.

The dye may make you feel warm and flushed and leave a
metallic taste in your mouth. Some people feel sick to their stomach or have a
headache. Tell your doctor how you are feeling.

Risks

There is some risk of problems with this test.

  • Some people who have a myelogram
    develop a headache, nausea, or vomiting after the test. The headache may last
    for 24 hours. In rare cases, a seizure may occur after the dye is put into the
    spinal canal.
  • There is a small risk of a seizure if the dye moves
    to the brain. This is why if or when you lie down, you need to keep your head
    raised higher than your body.
  • There is a small risk of infection at
    the needle site or bleeding into the spinal canal.
  • In rare cases,
    the hole made by the needle in the sac around the spine does not close
    normally. This can allow spinal fluid to leak out. This leak may need to be
    repaired through a procedure called an epidural blood patch. To do the patch, your doctor injects some of your own blood to cover the hole.
  • There is a small
    risk of having an
    allergic reaction to the dye. You will be given
    medicine for a reaction.
  • There is a risk of kidney problems if you
    take metformin (Glucophage) to control your
    diabetes.
  • In rare cases, inflammation of
    the spinal cord, weakness, numbness,
    paralysis, or loss of control of your bowel or bladder
    may develop.
  • Also in rare cases, the dye may cause blockage of the
    spinal canal. If this occurs, surgery is usually needed.
  • There is
    always a slight chance of damage to cells or tissue from radiation, including
    the low levels of radiation used for this test. But the chance of damage from
    the X-rays is usually very low compared with the benefits of the test.

After the test

Call
911 or other emergency services
right away if you have a seizure.

Call your doctor right away
if you:

  • Have any increase in pain, weakness, or numbness in your
    legs.
  • Have a severe headache or stiff neck, or if your eyes become very
    sensitive to light.
  • Have a headache that lasts longer than 24
    hours.
  • Have problems urinating or having a bowel
    movement.
  • Develop a fever.

Results

Your doctor will talk to you about the results of your test.

Myelogram
Normal:

The dye flows evenly through
the spinal canal.

The spinal cord is normal in
size, position, and shape. The nerves leaving the spinal cord are normal.

No narrowing or blockage of
the spinal canal is seen.

Abnormal:

The flow of dye is blocked or
diverted. This may be due to a ruptured herniated
disc,
spinal stenosis, a nerve injury, an
abscess, or a tumor.

Inflammation of the membrane
(arachnoid membrane) that covers the spinal cord is seen.

One or more nerves leaving the
spinal cord are pinched.

What Affects the Test

Reasons you may not be able to
have the test or why the results may not be helpful include:

  • Being pregnant. A myelogram is not usually done
    during pregnancy, because the radiation could damage the developing baby (fetus).
  • Not being
    able to lie still during the test.
  • Having had prior surgery on your
    spine or having a curved spine, severe
    arthritis, or some types of spinal injuries or
    defects. These conditions make it hard to place the needle with the dye into
    the spinal canal.

What To Think About

References

Other Works Consulted

  • Chernecky CC, Berger BJ (2013). Laboratory Tests and Diagnostic Procedures, 6th ed. St. Louis: Saunders.
  • Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.

Credits

ByHealthwise Staff
Primary Medical Reviewer Adam Husney, MD – Family Medicine
E. Gregory Thompson, MD – Internal Medicine
Specialist Medical Reviewer Howard Schaff, MD – Diagnostic Radiology

Current as ofOctober 9, 2017