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What myelography is and what it does Myelography is a relatively safe and painless radiologic
(x-ray) examination that is performed in the United States approximately
350,000 times a year. This test is done under local anesthesia and
provides important information about your spinal cord and the space
surrounding it. Your doctor has ordered this test to help make an accurate
diagnosis of your condition. The results help determine the best course
of treatment for you.
During the exam, a contrast medium (commonly called "dye")
will be injected into your spinal canal. This outlines or fills up
parts of the body that do not usually show up on an x-ray.
Who performs the test Although your personal physician requests this test,
a radiologist or neuroradiologist performs the actual examination.
A radiologist is a medical doctor who specializes in the use of x-rays
for diagnosis of medical conditions. The radiologist is assisted by
a radiologic (x-ray) technologist, a person who has years of experience
in the use of x-ray equipment. Together, these highly skilled professionals
will make sure that your myelography produces the best possible pictures
and that you are as comfortable as possible throughout the procedure.
Where it takes place Myelographies are usually performed in a hospital
but may also be performed in a radiologist’s office.
How long it takes The test itself usually takes from 30 to 90 minutes.
However, you may need to stay overnight in the hospital or
lie down for a while in the radiologist’s office after the test. Your
doctor or the office nurse will advise you how to plan your schedule
for the
day of the exam.
What you can do to help make it a success Myelography is a relatively comfortable procedure
with some associated risks that your physician will discuss with you.
Occasionally, some patients experience a slight discomfort from the
contrast medium. This occurs less frequently today because newer, safer
products called nonionic contrast media have been developed, and they
minimize most discomfort.
You can help assure a successful, comfortable procedure
by carefully following the instructions of your physician, the radiologist,
and the radiologic technologist. Please answer carefully any questions
they may ask about your general health. For example, be sure to tell
them if you are pregnant, diabetic, and/or allergic to any foods or
drugs. Let them know if you have had an allergic reaction to
contrast media in the past and give them a complete list of any medications
you may be taking now, including nonprescription medications. Tell
them if you have had or presently are being treated for an infection
in any part of your body.
What to do before your exam This guide provides a step-by-step description of
what to expect before, during, and after your myelography exam. But
please remember that it is only a guide. Some steps may vary depending
on your condition, the personal preferences of your physician, and
the standard procedures of the hospital or office where the test is
performed. As with other important diagnostic procedures, you may be
asked to sign an informed consent to undergo myelography. That is your
opportunity to ask any questions following a description of the risks,
benefits, and alternatives of the procedure. The contents of this guide
are for your information only and are not to be interpreted as taking
the place of informed consent. Do not hesitate to discuss your upcoming
myelography exam with your physician or the radiologist.
Following are several steps that your doctor may
ask you to take before you go to the hospital or radiologist’s office
for your exam. These same general steps may be recommended if you are
a hospitalized patient.
You may be asked to stop smoking If you are a smoker, your doctor may ask you to
stop smoking the day before your test and on the day of your test.
Smoking before the procedure may contribute to headaches or nausea
after the procedure.
You will probably need to increase your fluid intake It is important to stay well hydrated up until the
time of your exam. For this reason, your doctor may recommend that
you drink four to eight ounces of fluids every two hours while you
are awake. The regimen may start at noon the day before your test and
continue until it is time to go for your exam.
Your diet usually stays the same
You may follow your normal diet until two hours
before the procedure. If your exam is scheduled for the morning,
however, your doctor may ask you to have a clear liquid breakfast. This
consists
of liquids that you can see through, such as plain tea (with
sugar but no milk), apple juice, and broth. This type of meal provides
nourishment
and keeps you well hydrated.
You may be asked to empty your bladder Just before your test, you may be asked to empty
your bladder in order not to interrupt the procedure.
What happens during your exam
The radiologist administers a local anesthetic There are three different positions that may be
used for administration of the local anesthetic and the contrast medium.
Usually, you lie on your side on an x-ray table with your knees drawn
up and your chin tucked into your chest. However, you may be asked
to lie face down on the table with a pillow under your stomach to raise
your back, or you may sit on the edge of the examination table.
If cervical myelography (an examination of your
neck) is to be performed, then you will most likely lie on your stomach
on the examination table with your chin resting on a comfortable support.
Your hair will probably be moved away from your neck and covered with
a cap.
The radiologist will locate the space between your
vertebrae by fluoroscopy. A mark will be made near this spot. The area
will be cleaned with antiseptic solution, which may feel a little cold.
Then you may feel a pinprick in the skin, which becomes numb immediately.
(This is like the procedure used by dentists to numb the gums.)
The radiologist injects the contrast medium After the local anesthetic is administered, the
radiologist will insert a needle into the numbed area and inject the
contrast medium. You will be asked to keep your head up and your chin
extended while the dye is being injected. This helps to prevent headaches.
If you feel any uncomfortable sensations, be sure
to tell the radiologist right away. After the contrast medium is injected,
you may be asked to lie on your stomach or back with your head up for
the rest of the procedure.
The radiologic technologist takes a series
of x-rays The x-ray table will be tilted slowly to allow the
contrast medium to travel to different levels of the spinal column.
The radiologist will watch the flow of the dye on a TV screen that
is attached to a special kind of x-ray machine known as a fluoroscope.
Then the technologist will take a series of x-rays while the table
is tilted in various positions. The radiologist will ask you to lie
very still while this is done so that the pictures will be as clear
as possible. If you are having cervical myelography, the radiologist
may ask you not to cough, swallow, or move your head while the x-rays
are taken.
The whole procedure usually takes from 30 to 90
minutes. After it is over, there is usually no need to remove the contrast
medium from your spinal canal. (However, in some circumstances it may
be removed.) Most myelographic contrast media can be absorbed by your
body and eliminated naturally through your kidneys by urination.
If the examination is performed in a hospital, you
may be wheeled back to your room on a stretcher. The header of the
stretcher may be raised to help keep your head up.
If the exam is performed in a radiologist’s office,
you may be taken to a special room where you can rest for a few hours.
What to do after your exam
Lie still or sit quietly with your head up You will be asked to lie or sit still for approximately
four to six hours. The head of your hospital bed may be tilted
to an angle of 35-45 degrees so that you can lie in a sitting or semi-sitting
position with your head up. In some hospitals or in the
radiologist’s
office, you may be asked to sit in a wheelchair for a few
hours.
If you are released on the same day as the procedure,
someone should drive you home. At home, you may be asked to lie on
a bed against a few pillows to keep your head raised to a 35-45 degree
angle. You should never lie flat after a myelography exam and you should
keep your head raised to prevent headaches.
Approximately six hours after the procedure, you
may be encouraged to get up and walk around.
Drink plenty of fluids You may be allowed to eat normal meals after your
test and you will probably be encouraged to drink plenty of fluids.
Fluids will help eliminate the contrast medium from your body and help
prevent headaches.
Meet with your physician The radiologist will have your x-ray film developed,
study it, then forward the results to your personal physician. Your
physician will probably meet with you the day after your exam to discuss
the results and tell you what they mean to your health.
Conclusion We hope this information helps you better understand
what myelography is, what it does, and the role it plays
in maintaining your health. If you have any questions about your myelography
exam
that your physician has not answered, please write them down.
Then be sure to discuss these questions with your physician before you
go
to the hospital or radiologist’s office for your test. If you are a
hospitalized patient, be sure to ask your questions before
you are taken to the radiology department.
Glossary allergic: hypersensitive; a condition in
which the body reacts with an exaggerated response to a substance.
anesthesia: loss of feeling or sensation,
especially the sensation of pain.
antiseptic: a substance that stops the growth
of microorganisms such as bacteria and viruses.
cervical myelography: x-ray examination of
the neck after administration of a contrast medium.
contrast medium: a dye that is used to highlight
parts of the body that do not ordinarily show up on an x-ray.
fluoroscope: an instrument that allows the
visualization of movement of structures and/or contrast medium in the
body by means of x-ray shadows projected on a screen.
neuroradiologist: a physician who specializes
in the radiologic (x-ray) diagnosis of neurological (nerve) disorders.
Please note that this information is provided for
educational purposes only. It is not intended to substitute for informed
medical advice. The user of this site should not use this information
to diagnose or treat a health problem or disease without consulting with
a qualified health care provider.
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