Magnetic Resonance Imaging (MRI)
How It Is Done continued...
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 because 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 special belt strap may be used to sense your breathing or
heartbeat. This triggers the machine to take the scan at the right time.
Some people feel nervous (claustrophobic) inside the MRI magnet. If this
keeps you from lying still, you can be given a medicine (sedative) to help you
relax. Some MRI machines (called open MRI) are now made so that the magnet does
not enclose your entire body. Open MRI machines may be helpful if you are
claustrophobic, but they are not available everywhere. The pictures from an
open MRI may not be as good as those from a standard MRI machine. See pictures
of a standard MRI machine and an
open 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.
test usually takes 30 to 60 minutes but can take as long as 2 hours.