Indications and contraindications for an MRI scan
The following general rules are usually considered
by a physician before ordering an MRI scan for a patient.
Indications for when to get an MRI scan include:
-
After 4 to 6 weeks of leg pain, if the pain is
severe enough to warrant surgery.
-
After 3 to 6 months of low back pain, if the pain
is severe enough to warrant surgery.
-
If the pain is accompanied by constitutional symptoms
(such as loss of appetite, weight loss, fever, chills,
shakes, or severe pain when at rest). These symptoms
may indicate that the pain is due to a tumor or an
infection.
-
For patients who may have lumbar spinal stenosis
and are considering an epidural injection to alleviate
painful symptoms.
-
For patients who have not done well after having
surgery, if their pain symptoms do not get better
after 4 to 6 weeks.
Contraindications for undergoing an MRI scan include:
-
Patients who have a heart pacemaker may not have
an MRI scan
-
Patients who have a metallic foreign body (metal
sliver) in their eye, or who have an
aneurysm clip in their brain, cannot have an MRI
scan since the magnetic field may dislodge the metal.
-
Patients with severe claustrophobia may not be
able to tolerate an MRI scan, although
more open scanners are now available, and medical
sedation is available to make the test easier to
tolerate.
-
Patients who have had metallic devices placed
in their back (such as pedicle screws or
anterior interbody cages) can have an MRI scan, but
the resolution of the scan is often severely
hampered by the metal device and the spine is not
well imaged.
If a patient's symptoms match the indications for
an MRI scan, and there are no known risk factors (contraindications),
then an MRI scan can potentially be very beneficial
in helping plan further treatment.
By: Peter
F. Ullrich, Jr., MD
October 1999
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