MRI
Magnetic Resonance Imaging
WHAT
IS AN MRI?
HOW
IS THE MRI PERFORMED?
HOW
CAN I PREPARE FOR AN MRI?
WHAT
WILL THE MRI FEEL LIKE?
HOW
CAN I SCHEDULE AN APPOINTMENT?
WHAT
IS AN MRI?
A non-invasive procedure that uses magnets and radio waves to produce
a picture of the inside of the body area under investigation. Magnetic
resonance imaging (MRI) produces pictures of the inside of the body area
under investigation without exposing the body to ionizing radiation (X-rays).
The MRI scanner creates a strong magnetic field, which causes the atoms
within body tissues to align. A radio wave is directed at the body, triggering
the atoms within body cavity tissues to emit radio waves of their own.
This returned radio wave creates a signal (resonance) that is detected
by the scanner at thousands of angles around the body. The scanner sends
the signals to a computer, which processes the information and compiles
it into a 3-dimensional image of the tissue being scanned. Any 2-dimensional
"slice" can be projected as a visual image, which can be stored on photographic
film or videotape. MRI scans can see through bone and provide clear, detailed
pictures of soft tissues.
HOW
IS THE MRI PERFORMED?
The MRI scanner is in an area that has been shielded from outside magnetic
fields. You are asked to lie on a narrow table that can slide inside a
tunnel-like tube within the scanner. The scanner creates a magnetic field
around you, then pulses radio waves that are directed at the tissues in
question. Several sets of images are usually required, each taking from
2 to 15 minutes. The complete scan takes about 1/2 hour; some scans may
take more than one hour.
HOW
CAN I PREPARE FOR AN MRI?
No preparatory tests, diets, or medications are usually needed. Occasionally,
the person may be asked to fast for 4 to 6 hours prior to the scan. You
must sign a consent form. Because of the strong magnets, no metallic objects
are allowed into the room. Items such as jewelry, watches, credit cards,
and hearing aids can be damaged. Pins, hairpins, metal zippers, and similar
metallic items can distort the images. Frequent exposure to ferrous metals
(such as a sheet metal worker has) may require clearance film before the
MRI. A hospital gown may be recommended, or you may be allowed to wear
"sweats" or similar clothing without metal fasteners. Removable dental
work should be taken out just prior to the scan.
WHAT
WILL THE MRI FEEL LIKE?
There is no pain. The
magnetic field and radio waves are not felt. The primary discomfort is
the claustrophobic feeling that some people experience from being inside
the scanner. The table may be hard or cold, but you can request a blanket
or pillow. The machine produces loud thumping and humming noises. Ear
plugs are usually given to reduce the noise. A technologist observes you
during the entire procedure and may enter the room to speak to you or
may speak with you through an intercom in the scanner. Excessive movement
can blur MRI images. If you have difficulty lying still or are very anxious,
you may be given a sedative. There is no recovery required (unless you
have been sedated). After an MRI scan, you can resume normal diet, activity,
and medications.
HOW
CAN I SCHEDULE AN APPOINTMENT?
A physicians prescription is necessary to obtain an MRI. An appointment
can be made by calling the radiology department at 268-2283.
Have questions? Call
the radiology department at 268-2283.
See Related Pages:
RADIOLOGY
SERVICES
The Radiology Information Resource
for Patients:
www.RadiologyInfo.org
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