A Patient's Guide to MRI Scans of the Spine
What it is: The MRI scan is a fairly new test that does not use radiation.
By using magnetic and radio waves, the MRI creates computer-generated images.
The MRI is able to cut through multiple layers of the spine and show abnormalities
of soft tissues, such as nerves and ligaments. The MRI is probably the most
commonly used test for looking at the spine.
What the test shows: The MRI shows the spine in very clear detail. The
test gives information about the bones, ligaments, muscles, and discs. The test
also can be used to show early degeneration of the disc, such as the loss of
water in the nucleus pulposus - the earliest stage of disc degeneration. The
test can be used to show facet joint arthritis, spinal stenosis (narrowing of
spinal canal), or a herniated disc (protrusion or rupture of the intervertebral
disc). The test is useful for any condition where the anatomy of the spine and
its soft tissue contents need to be seen clearly.
What the test does not show: There is not much the MRI does not show.
However, X-rays are still best when fine detail about bones is needed. For problems
that are related to fractures or bone destruction from infection or tumor, many
spine specialists still rely on the CAT scan.
How the test is done: During an MRI scan, you will be asked to lie on
a table that slides into a machine with a large, round tunnel. The machine's
scanner then takes many pictures that are watched and monitored by a technician.
The MRI scanner is noisy. You may be offered headphones to listen to music while
the scan is taking place. The scanner is also pretty cramped; the tunnel that
you lie in does bother some patients who are extremely claustrophobic. You may
be given a mild sedative if you are claustrophobic to make the experience more
tolerable. There are also some newer MRI machines called Open MRI Scanners that
might be more comfortable for patients who experience claustrophobia. The procedure
takes 30-60 minutes.
What risks the test has: The test uses magnetic waves; however, there
appears to be no known risks associated with exposure to the waves. There are
problems if you have any metal objects in your body that could be attracted
to the strong magnetic field. For example, if you have some type of metal clip
that was used for a previous surgery, you will want to inform the technician.
You may also have X-rays taken of your skull before the test to make sure that
there are no metal fragments in your eyes or brain that could move when the
magnet is turned on.
What the test costs: A MRI scan of the spine usually has two costs associated
with the test. The first cost is the fee for actually doing the test. This is
called the "technical fee". The second cost is the fee of having a specialist,
such as a radiologist, read and interpret the test. This is called the "professional
fee". You may get two bills for this test: one from the hospital or clinic where
you had the MRI scan done, and one from the specialist who read the test.
Copyright © 2003 DePuy Acromed.
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