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MUSCULOSKELETAL/SPORTS
IMAGING
Procedure
Description
 Raleigh
Radiology offers a wide variety of studies to evaluate orthopedic
injuries and other bone and joint disorders. These studies
are performed and interpreted by fellowship-trained musculoskeletal
radiologists. We work closely with local orthopedists and
sports medicine physicians to provide optimal care to athletes.
Raleigh Radiology is proud to provide imaging for NCSU athletics
and the Carolina Hurricanes. MRI (magnetic resonance imaging)
uses radio waves and a strong magnetic field rather than X-rays
to provide clear and detailed pictures of internal organs
and tissues. The parts of the musculoskeletal system that
are most frequently imaged with MRI are the knee and shoulder.
However, MRI has also been used to study almost every joint
in the body, including the spine, hips, wrists, and hands.
MRI requires specialized equipment and expertise and allows
evaluation of some body structures that may not be as visible
with other imaging methods.
Patient
Preparation for the Procedure
Because the strong magnetic field used for MRI will pull on
any ferromagnetic metal object implanted in the body, MRI
staff will ask whether you have a prosthetic hip, an aneurysm
clip in the brain, heart pacemaker (or artificial heart valve),
implanted port (brand names Port-o-cath, Infusaport, Lifeport),
intrauterine device (IUD), or any metal plates, pins, screws,
or surgical staples in your body. In most cases, surgical
staples, plates, pins and screws pose no risk during MRI if
they have been in place for more than 4 to 6 weeks. Dyes used
in tattoos and permanent eyeliner may contain metallic iron
oxide and could heat up during MRI; however, this is rare.
You will be asked if you have ever had a bullet or shrapnel
in your body or ever worked with metal. If there is any question
of metal fragments, especially in the orbit (the bony cavity
around the eye), you may be asked to have an X-ray that will
detect any such metal objects. Tooth fillings usually are
not affected by the magnetic field, but they may distort images
of the facial area or brain, so the radiologist should be
aware of them. The same is true of braces, which may make
it hard to “tune” the MRI unit to your body. You
will be asked to remove anything that might degrade MRI images
of the head, including hairpins, jewelry, eyeglasses, hearing
aids, and any removable dental work.
The
radiologist or technologist may ask if you have any drug allergies
and whether you have undergone any surgery in the past. If
you are or might be pregnant, mention it to the MRI staff.
Some
patients who undergo MRI in an enclosed unit may feel confined
or claustrophobic. If you are not easily reassured, a sedative
may be administered. Roughly 1 in 20 patients will require
medication. High field Open Bore MRI is a new option for larger or claustrophobic patients.
Frequently
Asked Questions about Musculoskeletal/Sports Imaging
Q:
How is the procedure performed?
The patient is comfortably positioned on a special table that
slides into the MRI system opening where the magnetic field
is created. Then the radiologist and technologist leave the
room, and the individual MRI sequences are performed. The
patient will hear tapping noises during the exam. The tapping
is created when magnetic field gradient coils are switched
on and off to measure the MRI signal reflecting back out of
the patient’s body. The patient is able to communicate
with the radiologist or technologist at any time using an
intercom. Also, many MRI centers allow a friend or, if a child
is being examined, a parent, to stay in the room.
Depending
on how many images are needed, the exam will generally take
from 15 to 45 minutes, although a very detailed study may
take longer. You will be asked not to move during the actual
imaging process, but between sequences some movement is allowed.
Patients are generally required to remain still for only a
few seconds to a few minutes at a time.
Depending
on the part of the body being examined, a contrast material
may be used to enhance the visibility of certain tissues or
blood vessels. A small needle connected to an intravenous
line is placed in an arm or hand vein. The contrast material
is injected about two-thirds of the way through the exam.
When
the exam is over, the patient is asked to wait until the images
are examined to determine if more images are needed.
Q:
What will I experience during the procedure?
MRI causes no pain, but some patients can find it uncomfortable
to remain still during the examination. With enclosed units patients may experience
a sense of being “closed in,” though the more open
construction of newer MRI systems has done much to reduce
that reaction. Larger or claustrophobic patients have a new option with high field Open Bore MRI.
You may notice a warm feeling in the area under
examination; this is normal, but if it bothers you, the radiologist
or technologist should be told. If
an injection of contrast material is needed, there may be
discomfort at the injection site, and you may have a cool
sensation at the site during the injection. Most bothersome
to many patients are the loud tapping or knocking noises heard
at certain phases of imaging. Ear plugs may help.
Q:
What are the benefits vs. risks?
Benefits:
- MR
images of the soft tissue structures of the body, such as
the muscles, tendons, joints, and blood vessels, are clearer
and more detailed than with other imaging methods.
- MR
images can help identify the causes of pain, swelling, and
bleeding so that appropriate treatment can begin.
- MRI
contrast material is less likely to produce an allergic
reaction than the iodine-based materials used for conventional
X-rays and CT scanning.
- MRI
enables the detection of abnormalities, injuries, and diseases
that might be obscured by bone tissue with other imaging
methods.
- MRI
provides a fast, noninvasive way to assess a variety of
muscle and joint injuries and disorders.
- The
detail of MR images makes them an invaluable tool in early
diagnosis and evaluation of tumors.
- Exposure
to radiation is avoided.
Risks:
- An
undetected metal implant may be affected by the strong magnetic
field. It may cause some distortion of the images, or the
MRI system may have difficulty “tuning” to your
body if the implant is in the area being imaged.
- MRI
is generally avoided in the first 12 weeks of pregnancy.
Q:
What are the limitations of MRI of the Musculoskeletal System?
Bone is better imaged by conventional X-rays, and CT is preferred
for unstable patients with severe bleeding. MRI may not always
distinguish between tumor tissue and edema fluid and does
not detect calcium when this is present within a tumor. In
most cases the exam is safe for patients with metal implants,
with the exception of a few types of implants, so patients
should inform the technician of an implant prior to the test.
The exam must be used cautiously in early pregnancy. MRI often
costs more than CT scanning.
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