How It Is Done continued...
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 belt strap may be used to sense your breathing or
heartbeat. This triggers the machine to take the scan at the right time.
If you feel very nervous inside the machine, you may be given a sedative to help you
relax. You may be able to have an MRI with an open machine that doesn't enclose your entire body. But open MRI machines aren't available everywhere. The pictures from an
open MRI may not be as good as those from a standard 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.
An MRI usually takes 30 to 60 minutes but can take as long as 2 hours.
How It Feels
You will not have pain from the magnetic
field or radio waves used for the MRI. The table you lie on may feel hard,
and the room may be cool. You may be tired or sore from lying in one position
for a long time.
If a contrast material is used, you may feel some
coolness and flushing as it is put into your IV.
In rare cases,
you may feel:
- A tingling feeling in the mouth if you have
metal dental fillings.
- Warmth in the area being examined. This is
normal. Tell the technologist if you have nausea, vomiting, headache,
dizziness, pain, burning, or breathing problems.
There are no known harmful effects from the
strong magnetic field used for MRI. But the magnet is very powerful. The magnet
may affect pacemakers, artificial limbs, and other medical devices that contain
iron. The magnet will stop a watch that is close to the magnet. Any loose metal
object has the risk of causing damage or injury if it gets pulled toward the