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An MRI is a
test that uses a magnetic field and pulses of radio wave energy to make
pictures of the
spine. In many cases, an MRI gives different information
ultrasound, or a
CT scan. An MRI also may show
problems that cannot be seen with other imaging tests.
MRI, your body is placed inside a machine that contains a strong
magnet. Pictures from an MRI can be saved and
stored on a computer for further study. In some cases, a
contrast material may be used during the MRI to
show certain parts of the body more clearly.
The MRI can find changes in the spine and in other tissues. It also can find problems
such as infection or a tumor. MRI can look at the spine in the neck (cervical), upper back (thoracic), or lower back (lumbosacral). The
entire spine can be seen in one series of pictures to find a tumor. More
detailed pictures of one area, such as the lumbar spine, may be taken.
MRI may be used to check low
You may be able to have an MRI with an open machine that doesn't enclose your entire body. But open MRI machines aren't available everywhere. The pictures from an
open MRI may not be as good as those from a standard MRI machine.
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An MRI of
the spine is done to:
An MRI may be done using contrast material to see abnormal
tissue more clearly. The contrast material also may help tell the difference between
old surgical scars and a new disease or injury.
Before your MRI test, tell your doctor
and the MRI technologist if you:
You may be asked to sign a consent form that says you
understand the risks of the test and agree to have it done.
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?).
An MRI is usually done by an MRI technologist. The pictures are usually
read by a
radiologist. But some other types of doctors can also
read an MRI scan.
You will need to remove all metal objects
(such as hearing aids, dentures, jewelry, watches, and hairpins) from your body,
because these objects may be attracted to the powerful magnet used for the
You will need to take off all or most of your clothes,
depending on which area is examined. (You may be allowed to keep on your
underwear if it is not in the way.) You will be given a gown to use during the
test. If you are allowed to keep some of your clothes on, you should empty your
pockets of any coins and cards (such as credit cards or ATM cards) with scanner
strips on them. The MRI magnet may erase the information on the
During the test, you usually lie on your back on a table that
is part of the MRI scanner. Your head, chest, and arms may be held with straps
to help you remain still. The table will slide into the space that contains the
magnet. A device called a coil may be placed over or wrapped around the area to
be scanned. A belt strap may be used to sense your breathing or
heartbeat. This triggers the machine to take the scan at the right time.
If you feel very nervous inside the machine, you may be given a sedative to help you
relax. You may be able to have an MRI with an open machine that doesn't enclose your entire body. But open MRI machines aren't available everywhere. The pictures from an
open MRI may not be as good as those from a standard MRI machine.
Inside the scanner you will hear a fan and feel
air moving. You may also hear tapping or snapping noises as the MRI scans are
taken. You may be given earplugs or headphones with music to reduce the noise.
It is very important to hold completely still while the scan is being done. You
may be asked to hold your breath for short periods of time.
the test, you may be alone in the scanner room. But the technologist will watch
you through a window. You will be able to talk with the technologist through a
If contrast material is needed, the technologist
will put it in an
intravenous (IV) line in your arm. The material may be
given over 1 to 2 minutes. Then more MRI scans are done.
An MRI usually takes 30 to 60 minutes but can take as long as 2 hours.
You will not have pain from the magnetic
field or radio waves used for the MRI. The table you lie on may feel hard,
and the room may be cool. You may be tired or sore from lying in one position
for a long time.
If a contrast material is used, you may feel some
coolness when it is put into your IV.
In rare cases,
you may feel:
There are no known harmful effects from the
strong magnetic field used for MRI. But the magnet is very powerful. The magnet
may affect pacemakers, artificial limbs, and other medical devices that contain
iron. The magnet will stop a watch that is close to the magnet. Any loose metal
object has the risk of causing damage or injury if it gets pulled toward the
Metal parts in the eyes can damage the
retina. If you may have metal fragments in the eye, an
X-ray of the eyes may be done before the MRI. If metal is found, the MRI will
not be done.
Iron pigments in tattoos or tattooed eyeliner can
cause skin or eye irritation.
An MRI can cause a burn with some
medicine patches. Be sure to tell your health professional if you are wearing
There is a slight risk of an
allergic reaction if contrast material is used during
the MRI. But most reactions are mild and can be treated using medicine. There
also is a slight risk of an infection at the IV site.
If you breastfeed and are concerned about whether the dye used in this test is safe, talk to your doctor. Most experts believe that very little dye passes into breast milk and even less is passed on to the baby. But if you prefer, you can store some of your breast milk ahead of time and use it for a day or two after the test.
radiologist may discuss some of the results of the MRI
with you right after the test. Complete results are usually ready for your
doctor in 1 to 2 days.
The bones of the spine, discs, and nerves
No tumors, inflammation, or areas of nerve
damage in the spine are present.
No disease or bone loss in the spine is present.
No ruptured discs are present. There are no
structures pressing on a nerve.
No structural problems that have been
present from birth (congenital problems) are found.
Tumors, inflammation, or areas of nerve
damage in the spine are present. A disease of the spinal cord, such as
multiple sclerosis, is found.
Narrowing of the spinal canal (spinal stenosis) is present.
Broken bones or bone loss in the spine
caused by injury or disease, such as
arthritis, is found.
One or more
discs of the spine are bulging or ruptured or pressing
on a nerve.
A condition that has been present from
birth (congenital condition) is found in the spine or the
Reasons you may not be able to
have the test or why the results may not be helpful include:
Many modern medical devices that do not use
electronics—such as heart valves, stents, or clips—can be safely placed in most
MRI machines. But some newer MRI machines have stronger magnets. The safety of
MRI scans with these stronger MRI magnets in people with medical devices is not
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.
ByHealthwise StaffPrimary Medical ReviewerWilliam H. Blahd, Jr., MD, FACEP - Emergency MedicineE. Gregory Thompson, MD - Internal MedicineAdam Husney, MD - Family MedicineSpecialist Medical ReviewerHoward Schaff, MD - Diagnostic Radiology
Current as ofFebruary 19, 2016
Current as of:
February 19, 2016
William H. Blahd, Jr., MD, FACEP - Emergency Medicine
& E. Gregory Thompson, MD - Internal Medicine & Adam Husney, MD - Family Medicine & Howard Schaff, MD - Diagnostic Radiology
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